Variables: Difference between revisions

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This page gives a brief explanation of the format and meaning for input variables used by Yambo.  
This page gives a brief explanation of the many input variables used by Yambo. <br>
Eventually it will be split into separate pages per runlevel, with the Units/Formats appearing just on the main page.
Variables apply to the standard <code>yambo</code> '''executable''' unless indicated otherwise. <br>
Links can be made to runlevel sections with <nowiki>Variables#Initialization</nowiki> and to single variables with <nowiki>Variables#MaxGvecs</nowiki>, etc. Use the template ''var3''. Some characters will mess up the template, such as equal signs - this may explain why some of your text is missing.
'''Default''' values are read from the indicated database file unless stated otherwise.<br>
===Units===
Required '''verbosity''' flags are indicated where appropriate.
 
'''Units''' can have the following values:
* None = no unit
* None = no unit
* RL = number of G-vectors
* RL = number of G-vectors
Line 12: Line 14:
* Angle = deg, rad -->
* Angle = deg, rad -->


===Formats===
'''Formats''' are described on the [[Format]] page.
* Integer = integer value
* Real = real value
* Complex = <code>( real part , imag part )</code>
* String = string
* Range = <code>Lower limit | Upper limit |</code>(in the specified Unit or integer values)
* Scissors = <code>Shift | CB stretch | VB stretch |</code> (Energy | Real | Real)
* Vector = <code>x | y | z  |</code> (in Cartesian coordinates, sandwiched by %)
Ranges can also be split on multiple lines.
 
===Initialization===<!--section anchor-->
<span id="MaxGvecs"></span>
{{var3|MaxGvecs|RL/Energy|Integer/Real|Number of G-vectors in screening|This determines the size of the dielectric matrix in G-space. Needed for inclusion of local field effects. It should be much smaller than the number of G-vectors needed to expand the wavefunctions. It needs careful convergence.}}


===Optics-basic===<!--section anchor-->
'''DO NOT EDIT THIS PAGE DIRECTLY!!! CHANGES WILL BE LOST!!!'''
<span id="Chimod">  <!--single variable anchor-->
{{var3|Chimod|None|String|Type of kernel in TDDFT Dyson equation.|Do not set this manually - set using the appropriate '''-k''' command line option. Allowed values: IP/Hartree/ALDA/LRC/BSfxc. IP indicates no kernel (independent particle level/RPA without local fields).}}
</span>
<span id="NGBlkXd">  <!--single variable anchor-->
{{var3|NGBlkXd|RL/Energy|Integer/Real|Number of G-vectors or energy cut off in the screening.|Determines the size of the dielectric matrix in G-space. Needed for inclusion of local field effects. It should be much smaller than the number of G-vectors needed to expand the wavefunctions. It needs careful convergence.  }}
</span>
<span id="QpntsRXd">  <!--single variable anchor-->
{{var3|QpntsRXd|None|Integer range|Range of indexes of q-points/transferred momenta to be computed.|Set to 1 1 to select just the long wavelength term. }}
</span>
<span id="BndsRnXd">  <!--single variable anchor-->
{{var3|BndsRnXd|None|Integer range|Range of bands included in the sum.|Range of bands incluein blah blah }}
</span>
<span id="EnRngeXd">  <!--single variable anchor-->
{{var3|EnRngeXd|Energy|Range|Energy range the spectrum is calculated across.|Energy range blah blah }}
</span>
<span id="DmRngeXd">  <!--single variable anchor-->
{{var3|DmRngeXd|Energy|Range|Determines the damping used across the requested spectral range.|Typically this is kept constant. If different values are used, the damping at each energy will be interpolated linearly. This can be useful when poor k-point sampling leads to large oscillations at higher energy.}}
</span>
<span id="ETStpsXd">  <!--single variable anchor-->
{{var3|ETStpsXd|None|Integer|Number of energy steps.|Determines the number of steps in energy the response function/spectrum is computed for in the desired range defined by EnRngeXd. }}
</span>
<span id="LongDrXd">  <!--single variable anchor-->
{{var3|LongDrXd|Length|Vector|Electric field direction.|Electric field direction}}
</span>


===Optics-advanced=== <!--section anchor  '''Here anything needing verbosity''' -->
<!-- Eventually it will be split into separate pages per runlevel, with the Units/Formats appearing just on the main page.
<span id="FFTGvecs">  <!--single variable anchor-->
Links can be made to runlevel sections with <nowiki>Variables#Initialization</nowiki> and to single variables with <nowiki>Variables#MaxGvecs</nowiki>, etc. Use the template ''var3''. Some characters will mess up the template, such as equal signs - this may explain why some of your text is missing. THIS CAN BE FIXED WITH NAMED OPTIONS -->
{{var3|FFTGvecs|RL/Energy|Integer/Real|Number of G-vectors or energy cut off for expanding the wavefunctions/FFT transforms| It needs careful convergence. Determines the memory needed.}}
</span>
<span id="DrudeWX"> <!--single variable anchor-->
{{var3|DrudeWXd|Energy|Complex|Drude plasmon energy and inverse lifetime.|Drudes }}
</span>


===Coulomb cutoff===
<span id="CutRadius">  <!--single variable anchor-->
{{var3|CutRadius|Length|Real|Sphere/cylinder radius.|TIP}}
</span>
<span id="CUTBox">  <!--single variable anchor-->
{{var3|CUTBox|Length|Vector|Box sides.|BOX}}
</span>
<span id="CUTGeo">  <!--single variable anchor-->
{{var3|CUTGeo|None|String|Cutoff geometry.|Allowed values are: "box/cylinder/sphere X/Y/Z/XY...", e.g. "box xy" or "cylinder y".}}
</span>


===GW===<!--section anchor-->


<span id="EXXRLvcs"> <!--single variable anchor-->
===All Variables (alphabetical order)===
{{var3|EXXRLvcs|RL/Energy|Integer/Real|Number of G-vectors used in the sum of the exchange self-energy Sx.| It needs careful convergence: not particularly time consuming, large values can be used to ensure convergence. }}
<code>[[Variables#BDmRange|BDmRange]]</code> <code>[[Variables#BEnRange|BEnRange]]</code> <code>[[Variables#BEnSteps|BEnSteps]]</code> <code>[[Variables#BLongDir|BLongDir]]</code> <code>[[Variables#BndsRnXd|BndsRnXd]]</code> <code>[[Variables#BndsRnXp|BndsRnXp]]</code> <code>[[Variables#BoseCut|BoseCut]]</code> <code>[[Variables#BoseTemp|BoseTemp]]</code> <br>
</span>
<code>[[Variables#BS_CPU|BS_CPU]]</code> <code>[[Variables#BS_nCPU_LinAlg_DIAGO|BS_nCPU_LinAlg_DIAGO]]</code> <code>[[Variables#BS_nCPU_LinAlg_INV|BS_nCPU_LinAlg_INV]]</code> <code>[[Variables#BS_ROLEs|BS_ROLEs]]</code> <code>[[Variables#bse|bse]]</code> <code>[[Variables#BSEBands|BSEBands]]</code> <code>[[Variables#BSEmod|BSEmod]]</code> <code>[[Variables#BSENGBlk|BSENGBlk]]</code> <br>
<span id="QPkrange "> <!--single variable anchor-->
<code>[[Variables#BSENGexx|BSENGexx]]</code> <code>[[Variables#BSEPSInvTrs|BSEPSInvTrs]]</code> <code>[[Variables#BSHayTrs|BSHayTrs]]</code> <code>[[Variables#bsk|bsk]]</code> <code>[[Variables#BSKmod|BSKmod]]</code> <code>[[Variables#bss|bss]]</code> <code>[[Variables#BSSInvKdiag|BSSInvKdiag]]</code> <code>[[Variables#BSSInvMode|BSSInvMode]]</code> <br>
{{var3|QPkrange| None | Integer range | First and last Indexes of kpoints and bands the self energy correction is calculated | If interested in non consecutive kpoints or bands multiple rows can be also considered }}
<code>[[Variables#BSSInvPFratio|BSSInvPFratio]]</code> <code>[[Variables#BSSmod|BSSmod]]</code> <code>[[Variables#BSSPertWidth |BSSPertWidth ]]</code> <code>[[Variables#CGrdSpXd|CGrdSpXd]]</code> <code>[[Variables#chi|chi]]</code> <code>[[Variables#ChiLinAlgMod|ChiLinAlgMod]]</code> <code>[[Variables#Chimod|Chimod]]</code> <code>[[Variables#cohsex|cohsex]]</code> <br>
</span>
<code>[[Variables#CUTBox|CUTBox]]</code> <code>[[Variables#CUTCol_test|CUTCol_test]]</code> <code>[[Variables#CUTCylLen|CUTCylLen]]</code> <code>[[Variables#CUTGeo|CUTGeo]]</code> <code>[[Variables#CUTRadius|CUTRadius]]</code> <code>[[Variables#CUTwsGvec|CUTwsGvec]]</code> <code>[[Variables#DbGdQsize|DbGdQsize]]</code> <code>[[Variables#DbGdQsize|DbGdQsize]]</code> <br>
<code>[[Variables#DBsFRAGpm|DBsFRAGpm]]</code> <code>[[Variables#DBsIOoff|DBsIOoff]]</code> <code>[[Variables#DIP_Threads|DIP_Threads]]</code> <code>[[Variables#DipApproach|DipApproach]]</code> <code>[[Variables#DipApproach|DipApproach]]</code> <code>[[Variables#DipPDirect|DipPDirect]]</code> <code>[[Variables#DipPDirect|DipPDirect]]</code> <code>[[Variables#DmERefXd|DmERefXd]]</code> <br>
<code>[[Variables#DmRngeXd|DmRngeXd]]</code> <code>[[Variables#DmRngeXp|DmRngeXp]]</code> <code>[[Variables#DrClassic|DrClassic]]</code> <code>[[Variables#DrudeWBS|DrudeWBS]]</code> <code>[[Variables#DrudeWXd|DrudeWXd]]</code> <code>[[Variables#dScStep|dScStep]]</code> <code>[[Variables#DysSolver|DysSolver]]</code> <code>[[Variables#EhEngyXd|EhEngyXd]]</code> <br>
<code>[[Variables#ElecTemp|ElecTemp]]</code> <code>[[Variables#Em1Anys|Em1Anys]]</code> <code>[[Variables#em1d|em1d]]</code> <code>[[Variables#em1s|em1s]]</code> <code>[[Variables#EMStpsXd|EMStpsXd]]</code> <code>[[Variables#EnRngeXd|EnRngeXd]]</code> <code>[[Variables#EnRngeXp|EnRngeXp]]</code> <code>[[Variables#ETStpsXd|ETStpsXd]]</code> <br>
<code>[[Variables#ETStpsXp|ETStpsXp]]</code> <code>[[Variables#EvalCurrent|EvalCurrent]]</code> <code>[[Variables#ExtendOut |ExtendOut ]]</code> <code>[[Variables#ExtF_Dir|ExtF_Dir]]</code> <code>[[Variables#ExtF_kind|ExtF_kind]]</code> <code>[[Variables#EXXRLvcs|EXXRLvcs]]</code> <code>[[Variables#EXXRLvcs|EXXRLvcs]]</code> <code>[[Variables#FFTGvecs|FFTGvecs]]</code> <br>
<code>[[Variables#FrSndOrd|FrSndOrd]]</code> <code>[[Variables#FxcGRLc|FxcGRLc]]</code> <code>[[Variables#Gauge|Gauge]]</code> <code>[[Variables#GbndRnge|GbndRnge]]</code> <code>[[Variables#GDamping|GDamping]]</code> <code>[[Variables#GDmRnge|GDmRnge]]</code> <code>[[Variables#GEnRnge|GEnRnge]]</code> <code>[[Variables#GEnSteps|GEnSteps]]</code> <br>
<code>[[Variables#GfnQP_E|GfnQP_E]]</code> <code>[[Variables#GfnQP_N|GfnQP_N]]</code> <code>[[Variables#GfnQP_Wc|GfnQP_Wc]]</code> <code>[[Variables#GfnQP_Wc_dos|GfnQP_Wc_dos]]</code> <code>[[Variables#GfnQP_Wc_E|GfnQP_Wc_E]]</code> <code>[[Variables#GfnQP_Wv|GfnQP_Wv]]</code> <code>[[Variables#GfnQP_Wv_dos|GfnQP_Wv_dos]]</code> <code>[[Variables#GfnQP_Wv_E|GfnQP_Wv_E]]</code> <br>
<code>[[Variables#GfnQP_Z|GfnQP_Z]]</code> <code>[[Variables#GfnQPdb|GfnQPdb]]</code> <code>[[Variables#GrFnTpXd|GrFnTpXd]]</code> <code>[[Variables#GTermEn|GTermEn]]</code> <code>[[Variables#GTermKind|GTermKind]]</code> <code>[[Variables#gw0|gw0]]</code> <code>[[Variables#HARRLvcs|HARRLvcs]]</code> <code>[[Variables#HF_and_locXC|HF_and_locXC]]</code> <br>
<code>[[Variables#IDEm1Ref|IDEm1Ref]]</code> <code>[[Variables#IkSigLim|IkSigLim]]</code> <code>[[Variables#IkXLim|IkXLim]]</code> <code>[[Variables#K_Threads|K_Threads]]</code> <code>[[Variables#KfnQP_E|KfnQP_E]]</code> <code>[[Variables#KfnQP_N|KfnQP_N]]</code> <code>[[Variables#KfnQP_Wc|KfnQP_Wc]]</code> <code>[[Variables#KfnQP_Wc_dos|KfnQP_Wc_dos]]</code> <br>
<code>[[Variables#KfnQP_Wc_E|KfnQP_Wc_E]]</code> <code>[[Variables#KfnQP_Wv|KfnQP_Wv]]</code> <code>[[Variables#KfnQP_Wv_dos|KfnQP_Wv_dos]]</code> <code>[[Variables#KfnQP_Wv_E|KfnQP_Wv_E]]</code> <code>[[Variables#KfnQP_Z|KfnQP_Z]]</code> <code>[[Variables#KfnQPdb|KfnQPdb]]</code> <code>[[Variables#life |life ]]</code> <code>[[Variables#LifeTrCG|LifeTrCG]]</code> <br>
<code>[[Variables#LongDrXd|LongDrXd]]</code> <code>[[Variables#LongDrXp|LongDrXp]]</code> <code>[[Variables#LRC_alpha|LRC_alpha]]</code> <code>[[Variables#MaxGvecs|MaxGvecs]]</code> <code>[[Variables#MEM_tresh|MEM_tresh]]</code> <code>[[Variables#MetDamp|MetDamp]]</code> <code>[[Variables#Nelectro|Nelectro]]</code> <code>[[Variables#NewtDchk|NewtDchk]]</code> <br>
<code>[[Variables#NGsBlkXd|NGsBlkXd]]</code> <code>[[Variables#NLBands|NLBands]]</code> <code>[[Variables#NLCorrelation |NLCorrelation ]]</code> <code>[[Variables#NLDamping|NLDamping]]</code> <code>[[Variables#NLintegrator|NLintegrator]]</code> <code>[[Variables#NLLrcAlpha|NLLrcAlpha]]</code> <code>[[Variables#NLogCPUs|NLogCPUs]]</code> <code>[[Variables#nloptics|nloptics]]</code> <br>
<code>[[Variables#NLstep|NLstep]]</code> <code>[[Variables#NLtime|NLtime]]</code> <code>[[Variables#NLverbosity|NLverbosity]]</code> <code>[[Variables#NoCondSumRule|NoCondSumRule]]</code> <code>[[Variables#NonPDirs|NonPDirs]]</code> <code>[[Variables#OccTresh|OccTresh]]</code> <code>[[Variables#OnMassShell |OnMassShell ]]</code> <code>[[Variables#optics|optics]]</code> <br>
<code>[[Variables#PAR_def_mode|PAR_def_mode]]</code> <code>[[Variables#PAR_def_mode|PAR_def_mode]]</code> <code>[[Variables#PPAPntXp|PPAPntXp]]</code> <code>[[Variables#Qdirection|Qdirection]]</code> <code>[[Variables#QPerange|QPerange]]</code> <code>[[Variables#QPerange|QPerange]]</code> <code>[[Variables#QpgFull|QpgFull]]</code> <code>[[Variables#QPkrange|QPkrange]]</code> <br>
<code>[[Variables#QPkrange|QPkrange]]</code> <code>[[Variables#QpntsRXd|QpntsRXd]]</code> <code>[[Variables#QptCoord|QptCoord]]</code> <code>[[Variables#QShiftOrder|QShiftOrder]]</code> <code>[[Variables#RandGvec|RandGvec]]</code> <code>[[Variables#RandQpts|RandQpts]]</code> <code>[[Variables#Reflectivity|Reflectivity]]</code> <code>[[Variables#rim_cut|rim_cut]]</code> <br>
<code>[[Variables#SE_CPU|SE_CPU]]</code> <code>[[Variables#SE_ROLEs|SE_ROLEs]]</code> <code>[[Variables#SE_Threads|SE_Threads]]</code> <code>[[Variables#setup|setup]]</code> <code>[[Variables#ShiftedPaths|ShiftedPaths]]</code> <code>[[Variables#ShiftedPaths|ShiftedPaths]]</code> <code>[[Variables#StdoHash|StdoHash]]</code> <code>[[Variables#tddft|tddft]]</code> <br>
<code>[[Variables#UseDipoles|UseDipoles]]</code> <code>[[Variables#UseNLCC|UseNLCC]]</code> <code>[[Variables#VXCRLvcs|VXCRLvcs]]</code> <code>[[Variables#WehCpl|WehCpl]]</code> <code>[[Variables#WehDiag|WehDiag]]</code> <code>[[Variables#WFbuffIO|WFbuffIO]]</code> <code>[[Variables#WRbsWF|WRbsWF]]</code> <code>[[Variables#X_all_q_CPU|X_all_q_CPU]]</code> <br>
<code>[[Variables#X_all_q_nCPU_LinAlg_INV|X_all_q_nCPU_LinAlg_INV]]</code> <code>[[Variables#X_all_q_ROLEs|X_all_q_ROLEs]]</code> <code>[[Variables#X_finite_q_CPU|X_finite_q_CPU]]</code> <code>[[Variables#X_finite_q_nCPU_LinAlg_INV|X_finite_q_nCPU_LinAlg_INV]]</code> <code>[[Variables#X_finite_q_ROLEs|X_finite_q_ROLEs]]</code> <code>[[Variables#X_q_0_CPU|X_q_0_CPU]]</code> <code>[[Variables#X_q_0_nCPU_LinAlg_INV|X_q_0_nCPU_LinAlg_INV]]</code> <code>[[Variables#X_q_0_ROLEs|X_q_0_ROLEs]]</code> <br>
<code>[[Variables#X_Threads|X_Threads]]</code> <code>[[Variables#XfnQP_E|XfnQP_E]]</code> <code>[[Variables#XfnQP_N|XfnQP_N]]</code> <code>[[Variables#XfnQP_Wc|XfnQP_Wc]]</code> <code>[[Variables#XfnQP_Wc_dos|XfnQP_Wc_dos]]</code> <code>[[Variables#XfnQP_Wc_E|XfnQP_Wc_E]]</code> <code>[[Variables#XfnQP_Wv|XfnQP_Wv]]</code> <code>[[Variables#XfnQP_Wv_dos|XfnQP_Wv_dos]]</code> <br>
<code>[[Variables#XfnQP_Wv_E|XfnQP_Wv_E]]</code> <code>[[Variables#XfnQP_Z|XfnQP_Z]]</code> <code>[[Variables#XfnQPdb|XfnQPdb]]</code> <br>


===BSK===<!--section anchor-->
===Global options===
<span id=Nelectro></span>
{{var-basic|Nelectro|None|Real}}{{var-default|From ns.db1}}{{var-verbosity|gen}}
{{var-short|Number of electrons}}
{{var-usage|Change to shift the Fermi level by hand.}}
<span id=ElecTemp></span>
{{var-basic|ElecTemp|Energy|Real}}{{var-default|0.000}}{{var-verbosity|gen}}
{{var-short|Electronic Temperature}}
{{var-usage|}}
<span id=BoseTemp></span>
{{var-basic|BoseTemp|Energy|Real}}{{var-default|-1}}{{var-verbosity|gen}}
{{var-short|Bosonic Temperature}}
{{var-usage|}}
<span id=OccTresh></span>
{{var-basic|OccTresh|None|Real}}{{var-default|1.00E-05}}{{var-verbosity|gen}}
{{var-short|Occupation treshold (metallic bands)}}
{{var-usage|}}
<span id=StdoHash></span>
{{var-basic|StdoHash|None|Integer}}{{var-default|40}}{{var-verbosity|io}}
{{var-short|Number of hashes in live-timing output.}}
{{var-usage|Might be useful to increase for very long jobs, or if the code is hanging.}}
<span id=DBsIOoff></span>
{{var-basic|DBsIOoff|None|String}}{{var-default|none}}{{var-verbosity|io}}
{{var-short|List of databases not written to disk}}
{{var-usage|Space-separated list of DB with NO I/O. DB is (DIP,X,HF,COLLs,J,GF,CARRIERs,OBS,W,SC,BS,ALL). No ndb.* file is written. }}
::Example: DBsIOoff= "DIP" means ndb.dip_iR_and_P_fragment_* is not written, but stored in memory if Yambo needs it.
<span id=DBsFRAGpm></span>
{{var-basic|DBsFRAGpm|None|String}}{{var-default|none}}{{var-verbosity|io}}
{{var-short|List of databases to be fragmented}}
{{var-usage|Space-separated list of +DB to FRAG and -DB to NOT FRAG, where DB is (DIP,X,W,HF,COLLS,K,BS,QINDX,RT,ELP. Fragments the database. Smaller files (e.g. ndb.em1s_fragment_*) are created instead of a large one (e.g. ndb.em1s). Faster read/write operations in parallel runs}}
<span id=WFbuffIO></span>
{{var-basic|WFbuffIO|None|Flag}}{{var-default|Off}}{{var-verbosity|io}}
{{var-short|Wave-functions buffered I/O}}
{{var-usage|Parts of the WFs are stored by the node. Nodes communicate when these elements are needed. Memory heavy.}}
<span id=MEM_tresh></span>
{{var-basic|MEM_tresh|Kb|Integer}}{{var-default|10000}}{{var-verbosity|gen}}
{{var-short|Threshold on traced memory allocations/deallocations}}
{{var-usage|}}
<span id=NLogCPUs></span>
{{var-basic|NLogCPUs|None|Integer}}{{var-verbosity|par}}
{{var-short|Live-timing CPU`s (0 for all)}}
{{var-usage|Number of CPUs that write a LOG file. 0 means all CPUs.}}
<span id=PAR_def_mode></span>
{{var-basic|PAR_def_mode|None|String}}{{var-default|balanced}}{{var-verbosity|par}}
{{var-short|Parallelization mode ("balanced"/"memory"/"workload")}}
{{var-usage|You can set "memory" to save memory}}
<span id=FFTGvecs></span>
{{var-basic|FFTGvecs|RL/Energy|Integer/Real}}{{var-verbosity|RL}}
{{var-short|Number of G-vectors or energy cut off for expanding the wavefunctions/FFT transforms}}
{{var-usage|Determines size (memory) of calculation. Corresponds to cutoff in DFT calculation; can be much less than geometry cutoff. It needs careful convergence. }}
===Initialization===
<span id=setup></span>
{{var-basic|setup|None|String}}
{{var-short|Runlevel name}}
{{var-usage|Activate with -i option}}
<span id=MaxGvecs></span>
{{var-basic|MaxGvecs|RL/Energy|Integer/Real}}{{var-verbosity|RL}}
{{var-short|Maximum number of G-vectors that can be used by code}}
{{var-usage|}}
<span id=IkSigLim></span>
{{var-basic|IkSigLim|Range|Integer }}{{var-verbosity|kpt}}
{{var-short|QP K-points indices range}}
{{var-usage|}}
<span id=IkXLim></span>
{{var-basic|IkXLim||}}{{var-verbosity|kpt}}
{{var-short|}}
{{var-usage|}}
<span id=QptCoord></span>
{{var-basic|QptCoord||}}{{var-verbosity|kpt}}
{{var-short|}}
{{var-usage|}}
===Random integration method and cutoff Coulomb potentials===
<span id=rim_cut></span>
{{var-basic|rim_cut|None|String}}
{{var-short|Runlevel name}}
{{var-usage|Activate with -r option}}
<span id=RandQpts></span>
{{var-basic|RandQpts|RL|Integer}}
{{var-short|Number of random q-points in the BZ to perform Monte Carlo Integration,}}
{{var-usage|It needs convergence: values like 10^6 can be used to ensure convergence. Needed for non 3D system to avoid divergences for small q, and needed to build cutoff potential with box shape}}  ''See also:'' <code>[[Variables#RandGvec|RandGvec]]</code>
<span id=CUTGeo></span>
{{var-basic|CUTGeo|None|String}}{{var-default|none}}
{{var-short|Cutoff geometry}}
{{var-usage|Allowed values are: "box/cylinder/sphere/ws X/Y/Z/XY...", e.g. "box xy" or "cylinder y". WS is the suggested option for orthorhombic cells. Use sphere (0D) for molecules, cylinder (1D) for polymers and nanotubes, box (0D, 1D, 2D) for all geometries. XYZ: cut in all directions. Box: XY: cut in XY only. Cylinder X/Y/Z indicates cylinder axis. When using Box shapes, the RIM is also needed to calculate the potential. In Box for large enough boxes assigns Box side slighlty smaller than the cell box. In order to use the box a previous RandQpts  (rim_cut) is needed.}}  ''See also:'' <code>[[Variables#CUTBox|CUTBox]]</code><code>[[Variables#CUTRadius|CUTRadius]]</code><code>[[Variables#CUTCylLen|CUTCylLen]]</code><code>[[Variables#CUTwsGvec|CUTwsGvec]]</code>
<span id=CUTBox></span>
{{var-basic|CUTBox|Length|Vector}}{{var-default|(0,0,0)}}
{{var-short|Dimensions of box}}
{{var-usage|Box side=0 means do not cut in that direction. }}
<span id=CUTRadius></span>
{{var-basic|CUTRadius|Length|Real}}
{{var-short|Sphere/cylinder radius.}}
{{var-usage|Cutoff radius used in spehere and cylinder geometry}}
<span id=CUTCylLen></span>
{{var-basic|CUTCylLen|Length|Real}}
{{var-short|Length for finite Cylinders}}
{{var-usage|CUTCylLen=0 indicates infinite cylinder}}
<span id=CUTwsGvec></span>
{{var-basic|CUTwsGvec|Energy|Real}}{{var-default|0.7}}
{{var-short|Energy cut off on modified component }}
{{var-usage|To be used together with CUTGeo="ws".Determines the number of components of the potential to be modified.  }}  ''See also:'' <code>[[Variables#CUTGeo|CUTGeo]]</code>
<span id=RandGvec></span>
{{var-basic|RandGvec|Energy|}}{{var-verbosity|RL}}
{{var-short|Number of G vectors the RIM is calculated at}}
{{var-usage|RandGvec=1 (gamma) is usually enough}}
<span id=QpgFull></span>
{{var-basic|QpgFull|None|Flag}}{{var-default|off}}{{var-verbosity|RL}}
{{var-short|}}
{{var-usage|Monte Carlo random integratio for the full coulomb matrix 1/|q+G||q+G'|}}
<span id=Em1Anys></span>
{{var-basic|Em1Anys||}}{{var-verbosity|RL}}
{{var-short|}}
{{var-usage|}}
<span id=IDEm1Ref></span>
{{var-basic|IDEm1Ref||}}{{var-verbosity|RL}}
{{var-short|}}
{{var-usage|}}
<span id=CUTCol_test></span>
{{var-basic|CUTCol_test|None|Flag}}{{var-default|off}}{{var-verbosity|RL}}
{{var-short|Provides in output the truncated Coulomb potential in real space}}
{{var-usage|Useful option for debugging purposes.}}
===Hartree-Fock Self-energy and Vxc===
<span id=HF_and_locXC></span>
{{var-basic|HF_and_locXC|None|String}}
{{var-short|Runlevel name}}
{{var-usage|Activate with -x}}
<span id=EXXRLvcs></span>
{{var-basic|EXXRLvcs|RL/Energy|Integer/Real}}{{var-default|MaXGvecs}}
{{var-short|Number of G-vectors used in the sum of the exchange self-energy Sx.}}
{{var-usage|It needs careful convergence. As it is not particularly time consuming, large values can be used to ensure convergence. Generally a large number is needed as the QP energies show a slow convergence. The calcualtion of the exchange part is rather fast.}}
<span id=VXCRLvcs></span>
{{var-basic|VXCRLvcs|RL/Energy|Integer/Real}}{{var-default|MaXGvecs}}
{{var-short|Number of G-vectors used in the evaluation of the density for the <Vxc> matrix element}}
{{var-usage|A large number is needed in order to have a precise cancellation with the ground state calculation, in particular when GGA potential are used. A good measure of the accuracy is to compare the E_xc value printed in Yambo report and QE output file.}}
<span id=QPkrange></span>
{{var-basic|QPkrange|None|Range}}{{var-default|All qp and all bands available.}}
{{var-short|Range of states (n,k) where GW/Sx elements are calculated}}
{{var-usage|Careful use of fewer k-points and bands reduces the calculation time; yambo will interpolate the rest. Format is: first k-point | last k-point | lower band | upper band. This can be split over several lines for multiple groups - see the Format page for examples.}}  ''See also:'' <code>[[Variables#QPerange|QPerange]]</code>
<span id=UseNLCC></span>
{{var-basic|UseNLCC|None|Flag}}{{var-default|off}}{{var-verbosity|qp}}
{{var-short|If present, add NLCC contributions to the charge density.}}
{{var-usage|Care is needed. Beware NLCC are included in the Vxc but not in the exchange part of the self energy that could be inconsistent. Suggestion: if possible use PP without NLCC.}}
<span id=QPerange></span>
{{var-basic|QPerange|None/Energy|Range}}{{var-verbosity|qp}}
{{var-short|Range of states (E,k) where GW/Sx elements are calculated}}
{{var-usage|Careful use of fewer k-points and bands reduces the calculation time; yambo will interpolate the rest. Format is: first k-point | last k-point | lower energy | upper energy. This can be split over several lines for multiple groups.}}  ''See also:'' <code>[[Variables#QPkrange|QPkrange]]</code>
<span id=SE_CPU></span>
{{var-basic|SE_CPU|None|String}}{{var-verbosity|par}}
{{var-short|CPUs for each role}}
{{var-usage|For consistency the product of the CPUs for each role has to be equal to the number of MPI tasks of the job}}
<span id=SE_ROLEs></span>
{{var-basic|SE_ROLEs|None|String}}{{var-verbosity|par}}
{{var-short|CPUs roles (q,qp,b)}}
{{var-usage|Here qp=quasiparticle states, q=transferred momenta, b=bands in G summation. MPI-b best memory distribution. MPI-qp no communication. MPI-q leads to load unbalance.}}  ''See also:'' <code>[[Variables#SE_ROLEs|SE_ROLEs]]</code>
<span id=SE_Threads></span>
{{var-basic|SE_Threads|None|Integer}}{{var-verbosity|par}}
{{var-short|Number of threads for self-energy}}
{{var-usage|Very efficient. To be effective the code should have been compiled with OMP support.}}
===GW===
<span id=cohsex></span>
{{var-basic|cohsex|None|String}}
{{var-short|Runlevel name}}
{{var-usage|}}
<span id=gw0></span>
{{var-basic|gw0|None|String}}
{{var-short|Runlevel name}}
{{var-usage|Activate with -g <opt> }}
<span id=life ></span>
{{var-basic|life |None|String}}
{{var-short|Runlevel name}}
{{var-usage|Activate with -l option.}}
<span id=QPkrange></span>
{{var-basic|QPkrange|None|Range}}{{var-default|From ns.db1 (all k-points, all bands)}}
{{var-short|K-points and band range where you want to calculate the GW correction.}}
{{var-usage|If interested in non consecutive kpoints or bands multiple rows can be also considered. The syntax is first kpoint | last kpoint | first band | last band}}
<span id=GbndRnge></span>
{{var-basic|GbndRnge|None|Range}}
{{var-short|Specifies the range of bands entering in the sum over states in the correlation part of the self energy}}
{{var-usage|It needs several empty states. Single quasiparticle states converges very slowly with respect GbndRnge, energy differences (e.g. gaps) behave better. See also GTermKind variable in order to speed up the convergences.This number is usually larger than the number of bands used to calculated the dielectricconstant. Single quasiparticle energies converge slowly with respect GbndRnge, energy difference behave better. You can use terminator technique to mitigate the slow dependence.}}
<span id=GDamping></span>
{{var-basic|GDamping||}}
{{var-short|Small damping in the Green's function definition, the delta parameter.}}
{{var-usage|The final result shouuld not depend on that, usually set at 0.1 eV}}
<span id=dScStep></span>
{{var-basic|dScStep|Energy|Real}}{{var-default|0.1}}
{{var-short|Energy step to evaluate Z factors}}
{{var-usage|}}
<span id=DysSolver></span>
{{var-basic|DysSolver||}}
{{var-short|Indicates method used to solve the Dyson equation}}
{{var-usage|"n" Newton linearization (First order expansion around KS eigenvalue), 's' non linear iterative secant method}}
<span id=LifeTrCG></span>
{{var-basic|LifeTrCG|None|Real}}{{var-default|100}}
{{var-short|Lifetime transition reduction (%)}}
{{var-usage|}}
<span id=GfnQPdb></span>
{{var-redirect|GfnQPdb|<code>[[Variables#KfnQPdb|KfnQPdb]]</code>}}
<span id=GfnQP_N></span>
{{var-redirect|GfnQP_N|<code>[[Variables#KfnQP_N|KfnQP_N]]</code>}}
<span id=GfnQP_E></span>
{{var-redirect|GfnQP_E|<code>[[Variables#KfnQP_E|KfnQP_E]]</code>}}
<span id=GfnQP_Z></span>
{{var-redirect|GfnQP_Z|<code>[[Variables#KfnQP_Z|KfnQP_Z]]</code>}}
<span id=GfnQP_Wv_E></span>
{{var-redirect|GfnQP_Wv_E|<code>[[Variables#KfnQP_Wv_E|KfnQP_Wv_E]]</code>}}
<span id=GfnQP_Wv></span>
{{var-redirect|GfnQP_Wv|<code>[[Variables#KfnQP_Wv|KfnQP_Wv]]</code>}}
<span id=GfnQP_Wv_dos></span>
{{var-redirect|GfnQP_Wv_dos|<code>[[Variables#KfnQP_Wv_dos|KfnQP_Wv_dos]]</code>}}
<span id=GfnQP_Wc_E></span>
{{var-redirect|GfnQP_Wc_E|<code>[[Variables#KfnQP_Wc_E|KfnQP_Wc_E]]</code>}}
<span id=GfnQP_Wc></span>
{{var-redirect|GfnQP_Wc|<code>[[Variables#KfnQP_Wc|KfnQP_Wc]]</code>}}
<span id=GfnQP_Wc_dos></span>
{{var-redirect|GfnQP_Wc_dos|<code>[[Variables#KfnQP_Wc_dos|KfnQP_Wc_dos]]</code>}}
<span id=GTermKind></span>
{{var-basic|GTermKind|None|String}}{{var-verbosity|qp}}
{{var-short|Type of terminator to accelarate onvergence with respect empty states}}
{{var-usage|Default is "none", possible options are "BG" for the Bruneval-Gonze terminator. See BG[1]. It speeds up the convergence with respect to number of empty bands.}}
<span id=GTermEn></span>
{{var-basic|GTermEn|Energy|}}{{var-verbosity|qp}}
{{var-short|Energy of the fictitious pole of the terminator}}
{{var-usage|}}
<span id=NewtDchk></span>
{{var-basic|NewtDchk||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=ExtendOut ></span>
{{var-basic|ExtendOut |None|Flag}}{{var-verbosity|qp}}
{{var-short|Extended output: Print more quantities in qp output files}}
{{var-usage|}}
<span id=OnMassShell ></span>
{{var-basic|OnMassShell ||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=QPerange></span>
{{var-basic|QPerange||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=GEnSteps></span>
{{var-basic|GEnSteps||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|-g s}}
<span id=GEnRnge></span>
{{var-basic|GEnRnge||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|-g s}}
<span id=GDmRnge></span>
{{var-basic|GDmRnge||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|-g s}}
===Screening===
<span id=em1d></span>
{{var-basic|em1d||String}}
{{var-short|Runlevel name}}
{{var-usage|}}
<span id=em1s></span>
{{var-basic|em1s||String}}
{{var-short|Runlevel name}}
{{var-usage|}}
<span id=NGsBlkXd></span>
{{var-basic|NGsBlkXd|RL/Energy|Integer/Real}}
{{var-short|Number of G-vectors or energy cut off in the screening (response block size)}}
{{var-usage|Determines the size of the dielectric matrix in G-space. Needed for inclusion of local field effects, it should be much smaller than the number of G-vectors needed to expand the wavefunctions (FFTGvecs). It needs careful convergence, and should be converged along with BndsRnXd. Depends strongly on the system inhomogeneity.}}  ''See also:'' <code>[[Variables#BndsRnXp|BndsRnXp]]</code><code>[[Variables#FFTGvecs|FFTGvecs]]</code>
<span id=PPAPntXp></span>
{{var-basic|PPAPntXp|Energy|Real}}{{var-default|1 Ha (27.2114eV)}}
{{var-short|Plasmon pole Imaginary Energy}}
{{var-usage|The self energy in the imaginary axis should be a smooth function so it should not have a strong dependence on this pole energy. Set it at an higher value of the plasmon energy (see EELS spectrum). this is the second frequency used to fit the Godby-Needs plasmon-pole model (PPM). If results depend consistently by changing this frequency, the PPM is not adequate for your calculation and it is need to gp beyond that, e.g. Real-axis.}}
<span id=BndsRnXp></span>
{{var-redirect|BndsRnXp|<code>[[Variables#BndsRnXd|BndsRnXd]]</code>}}
<span id=EnRngeXp></span>
{{var-redirect|EnRngeXp|<code>[[Variables#EnRngeXd|EnRngeXd]]</code>}}
<span id=DmRngeXp></span>
{{var-redirect|DmRngeXp|<code>[[Variables#DmRngeXd|DmRngeXd]]</code>}}
<span id=ETStpsXp></span>
{{var-redirect|ETStpsXp|<code>[[Variables#ETStpsXd|ETStpsXd]]</code>}}
<span id=LongDrXp></span>
{{var-redirect|LongDrXp|<code>[[Variables#LongDrXd|LongDrXd]]</code>}}
===Optics/chi in G-space===
<span id=optics></span>
{{var-basic|optics|None|String}}
{{var-short|Runlevel name: "Optics"}}
{{var-usage|Activate with -o <opt>. Optics runlevel.}}
<span id=chi></span>
{{var-basic|chi|None|String}}
{{var-short|Runlevel name: "Dyson equation for chi."}}
{{var-usage|Activate with -o c. Dyson equation for chi.}}
<span id=tddft></span>
{{var-basic|tddft|None|String}}
{{var-short|Runlevel name: "Use TDDFT kernel"}}
{{var-usage|Activate with -k alda or -k lrc. Use TDDFT kernel}}
<span id=Chimod></span>
{{var-basic|Chimod|None|String}}
{{var-short|Type of kernel in TDDFT Dyson equation}}
{{var-usage|Do not set this manually - set using the appropriate '''-k''' command line option. Allowed values: IP/Hartree/ALDA/LRC/BSfxc. IP indicates no kernel (independent particle level/RPA without local fields)}}
<span id=X_Threads></span>
{{var-basic|X_Threads|None|Integer}}
{{var-short|Number of threads for response functions}}
{{var-usage|efficient, need extra mem}}
<span id=DIP_Threads></span>
{{var-basic|DIP_Threads||}}
{{var-short|}}
{{var-usage|}}
<span id=QpntsRXd></span>
{{var-basic|QpntsRXd|None|Range}}
{{var-short|Range of indexes of q-points/transferred momenta to be computed.}}
{{var-usage|Set to 1 1 to select just the long wavelength term. Range from 1:nqpt.}}
<span id=BndsRnXd></span>
{{var-basic|BndsRnXd|None|Range}}
{{var-short|Bands range: Specifies the number of bands entering in the sum over states in the RPA response function}}
{{var-usage|It needs several empty states. See also GTermKind variable in order to speed up the convergences. Reduce range in order to lower memory. In metals it includes partially filled bands. See also EhEngyXd.}}  ''See also:'' <code>[[Variables#GTermKind|GTermKind]]</code>
<span id=EnRngeXd></span>
{{var-basic|EnRngeXd|Energy|Range}}
{{var-short|Energy range the spectrum is calculated across.}}
{{var-usage|Extremae of the energy range across which optical spectra will be computed.}}  ''See also:'' <code>[[Variables#EhEngyXd|EhEngyXd]]</code>
<span id=DmRngeXd></span>
{{var-basic|DmRngeXd|Energy|Range}}
{{var-short|Determines the damping used across the requested spectral range.}}
{{var-usage|Typically this is kept constant. If different values are used, the damping at each energy will be interpolated linearly. This can be useful when poor k-point sampling leads to large oscillations at higher energy.}}
<span id=ETStpsXd></span>
{{var-basic|ETStpsXd|None|Integer}}
{{var-short|Number of energy steps in computing X}}
{{var-usage|Determines the number of steps in energy the response function/spectrum is computed for in the desired range defined by EnRngeXd. In the case of a full frequency GW the range is fixed by the occupied/empty states included in the calculation, the number of frequency requires a careful check}}
<span id=LongDrXd></span>
{{var-basic|LongDrXd|Length|Vector}}
{{var-short|Electric field direction}}
{{var-usage|Pay attention how the system is oriented when treating non 3D systems and choose a direction in the plane/axis where your system lies}}
<span id=FxcGRLc></span>
{{var-basic|FxcGRLc||}}
{{var-short|XC-kernel size}}
{{var-usage|Needs convergence study. Much less than FFTGvecs}}
<span id=LRC_alpha></span>
{{var-basic|LRC_alpha|None|Real}}{{var-default|0.00}}
{{var-short|LRC fitting parameter alpha}}
{{var-usage|Long-range tail of the fxc kernel. Depends on the system: the larger the screening the smaller this parameter.}}
<span id=XfnQPdb></span>
{{var-redirect|XfnQPdb|<code>[[Variables#KfnQPdb|KfnQPdb]]</code>}}
<span id=XfnQP_N></span>
{{var-redirect|XfnQP_N|<code>[[Variables#KfnQP_N|KfnQP_N]]</code>}}
<span id=XfnQP_E></span>
{{var-redirect|XfnQP_E|<code>[[Variables#KfnQP_E|KfnQP_E]]</code>}}
<span id=XfnQP_Z></span>
{{var-redirect|XfnQP_Z|<code>[[Variables#KfnQP_Z|KfnQP_Z]]</code>}}
<span id=XfnQP_Wv_E></span>
{{var-redirect|XfnQP_Wv_E|<code>[[Variables#KfnQP_Wv_E|KfnQP_Wv_E]]</code>}}
<span id=XfnQP_Wv></span>
{{var-redirect|XfnQP_Wv|<code>[[Variables#KfnQP_Wv|KfnQP_Wv]]</code>}}
<span id=XfnQP_Wv_dos></span>
{{var-redirect|XfnQP_Wv_dos|<code>[[Variables#KfnQP_Wv_dos|KfnQP_Wv_dos]]</code>}}
<span id=XfnQP_Wc_E></span>
{{var-redirect|XfnQP_Wc_E|<code>[[Variables#KfnQP_Wc_E|KfnQP_Wc_E]]</code>}}
<span id=XfnQP_Wc></span>
{{var-redirect|XfnQP_Wc|<code>[[Variables#KfnQP_Wc|KfnQP_Wc]]</code>}}
<span id=XfnQP_Wc_dos></span>
{{var-redirect|XfnQP_Wc_dos|<code>[[Variables#KfnQP_Wc_dos|KfnQP_Wc_dos]]</code>}}
<span id=NonPDirs></span>
{{var-basic|NonPDirs||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=ChiLinAlgMod></span>
{{var-basic|ChiLinAlgMod||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=GrFnTpXd></span>
{{var-basic|GrFnTpXd||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|Greens function: T/R/r/Ta/Ra. "R" = resonant gives the causal response function}}
<span id=DmERefXd></span>
{{var-basic|DmERefXd||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=CGrdSpXd></span>
{{var-basic|CGrdSpXd||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=EMStpsXd></span>
{{var-basic|EMStpsXd||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=DrudeWXd></span>
{{var-basic|DrudeWXd|Energy|Complex}}{{var-verbosity|resp}}
{{var-short|Drude plasmon energy and inverse lifetime.}}
{{var-usage|}}
<span id=EhEngyXd></span>
{{var-basic|EhEngyXd|Energy|Range}}{{var-default|(-1,-1)}}{{var-verbosity|resp}}
{{var-short|Electron-hole energy range}}
{{var-usage|An alternative way to BndsRnXd to restrict transitions, but will not reduce memory}}
<span id=DrClassic></span>
{{var-basic|DrClassic||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=DipApproach></span>
{{var-basic|DipApproach||String}}{{var-default|G-space v}}{{var-verbosity|resp}}
{{var-short|Different ways to calculate dipole matrix elements}}
{{var-usage|}}
<span id=DipPDirect></span>
{{var-basic|DipPDirect||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=ShiftedPaths></span>
{{var-basic|ShiftedPaths||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=Qdirection></span>
{{var-basic|Qdirection||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=QShiftOrder></span>
{{var-basic|QShiftOrder||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=DbGdQsize></span>
{{var-basic|DbGdQsize||}}{{var-verbosity|resp}}
{{var-short|}}
{{var-usage|}}
<span id=PAR_def_mode></span>
{{var-basic|PAR_def_mode||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=X_q_0_CPU></span>
{{var-basic|X_q_0_CPU||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=X_q_0_ROLEs></span>
{{var-basic|X_q_0_ROLEs||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=X_q_0_nCPU_LinAlg_INV></span>
{{var-basic|X_q_0_nCPU_LinAlg_INV||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=X_finite_q_CPU></span>
{{var-basic|X_finite_q_CPU||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=X_finite_q_ROLEs></span>
{{var-basic|X_finite_q_ROLEs||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=X_finite_q_nCPU_LinAlg_INV></span>
{{var-basic|X_finite_q_nCPU_LinAlg_INV||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=X_all_q_CPU></span>
{{var-basic|X_all_q_CPU||}}
{{var-short|CPUs for each role}}
{{var-usage|}}
<span id=X_all_q_ROLEs></span>
{{var-basic|X_all_q_ROLEs||}}
{{var-short|CPUs roles (q,k,c,v)}}
{{var-usage|MPI-c,v best memory distribution. MPI-k efficient, some memory replication. MPI-q may lead to load unbalance.}}
<span id=X_all_q_nCPU_LinAlg_INV></span>
{{var-basic|X_all_q_nCPU_LinAlg_INV||}}
{{var-short|CPUs for matrix inv}}
{{var-usage|}}
===Optics/BSE in eh-space===
<span id=bse></span>
{{var-basic|bse|None|String}}
{{var-short|Runlevel name: "Bethe Salpeter Equation"}}
{{var-usage|Activate with -o b}}
<span id=K_Threads></span>
{{var-basic|K_Threads|None|Integer}}
{{var-short|Number of threads for response functions}}
{{var-usage|}}
<span id=BSEmod></span>
{{var-basic|BSEmod|None|String}}{{var-default|retarded}}
{{var-short|}}
{{var-usage|resonant/retarded/coupling}}
<span id=BSKmod></span>
{{var-basic|BSKmod|None|String}}{{var-default|IP}}
{{var-short|Bethe Salpeter kernel}}
{{var-usage|Do not set this manually: activate with the appropriate -k <opt> command line option, where opt is one of IP/Hartree/HF/ALDA/SEX.}}
<span id=BEnRange></span>
{{var-basic|BEnRange|Energy|Range}}{{var-default|[0:10] eV}}
{{var-short|Energy range for computing the macroscopic dielectric function using BSE}}
{{var-usage|}}
<span id=BDmRange></span>
{{var-basic|BDmRange|Energy|Range}}{{var-default|(0.10000 , 0.10000)}}
{{var-short|Broadening for the BSE calculation}}
{{var-usage|Lorentzian broadening changes linearly between the two values}}
<span id=BEnSteps></span>
{{var-basic|BEnSteps|None|Integer}}{{var-default|100}}
{{var-short|Number of evenly spaced energy points in spectrum}}
{{var-usage|}}
<span id=BLongDir></span>
{{var-basic|BLongDir|None|Vector}}{{var-default|(1,0,0)}}
{{var-short|Direction of the longitudinal perturbation}}
{{var-usage|}}
<span id=BSEBands></span>
{{var-basic|BSEBands|None|Range}}{{var-default|All bands}}
{{var-short|Bands range: Specifies the band states from which the electron-hole basis of the BSE kernel is constructed}}
{{var-usage|Choose few bands close to the Fermi level. Size scales rapidly with the number of bands: BSE is rewritten as an eigenvalue problem for the 2 particle Hamiltonian: size of matrix [Nv x Nc x NKBZ ] x [Nv x Nc x NKBZ]}}
<span id=KfnQPdb></span>
{{var-basic|KfnQPdb|None|String}}{{var-verbosity|qp}}
{{var-short|Database for QP corrections.}}
{{var-usage|From a previous GW calculation. An interpolation of the missing QP-values on the basis of the QP-database is available}}  ''See also:'' <code>[[Variables#KfnQP_E|KfnQP_E]]</code>
::Format: "<what> < <path>/ndb.QP" with <what> = E,W,Z for QP energy correction, QP width and renormalization factor. For example, from a previous GW calculation use KfnQPdb= "E < ./SAVE/ndb.QP"
<span id=KfnQP_N></span>
{{var-basic|KfnQP_N|None|Integer}}{{var-verbosity|qp}}
{{var-short|Interpolation neighbours?}}
{{var-usage|}}
<span id=KfnQP_E></span>
{{var-basic|KfnQP_E|eV/None/None|Scissors}}{{var-verbosity|qp}}
{{var-short|QP corrections using a scissor operator and stretching coefficients for the conduction/valence bandwidths.}}
{{var-usage|Insert values from a previous GW calculation or experiment. This is a lighter way to include GW corrections than KfnQP_E. Format is: scissor | stretch conduction | stretch valence.}}  ''See also:'' <code>[[Variables#KfnQPdb|KfnQPdb]]</code>
<span id=KfnQP_Z></span>
{{var-basic|KfnQP_Z||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=KfnQP_Wv_E></span>
{{var-basic|KfnQP_Wv_E||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=KfnQP_Wv></span>
{{var-basic|KfnQP_Wv||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=KfnQP_Wv_dos></span>
{{var-basic|KfnQP_Wv_dos||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=KfnQP_Wc_E></span>
{{var-basic|KfnQP_Wc_E||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=KfnQP_Wc></span>
{{var-basic|KfnQP_Wc||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=KfnQP_Wc_dos></span>
{{var-basic|KfnQP_Wc_dos||}}{{var-verbosity|qp}}
{{var-short|}}
{{var-usage|}}
<span id=BoseCut></span>
{{var-basic|BoseCut||}}{{var-verbosity|gen}}
{{var-short|}}
{{var-usage|}}
<span id=DbGdQsize></span>
{{var-basic|DbGdQsize|None|Real}}{{var-verbosity|resp}}
{{var-short|Percentual of the total DbGd transitions to be used}}
{{var-usage|}}
<span id=DipApproach></span>
{{var-basic|DipApproach|None|String}}{{var-default|G-space v}}{{var-verbosity|resp}}
{{var-short|how dipoles are calculated:G-space v}}
{{var-usage|Options are: G-space v/R-space x/Covariant/Shifted grids}}
<span id=DipPDirect></span>
{{var-basic|DipPDirect|None|Flag}}{{var-default|off}}{{var-verbosity|resp}}
{{var-short|Directly compute <v> also when using other approaches for dipoles}}
{{var-usage|}}
<span id=ShiftedPaths></span>
{{var-basic|ShiftedPaths|None|String}}{{var-verbosity|resp}}
{{var-short|Shifted grids paths (separated by a space)}}
{{var-usage|}}
<span id=Gauge></span>
{{var-basic|Gauge|None|String}}{{var-default|length}}{{var-verbosity|resp}}
{{var-short|Switch between lenght or velocity gauge}}
{{var-usage|}}
<span id=NoCondSumRule></span>
{{var-basic|NoCondSumRule|None|Flag}}{{var-default|off}}{{var-verbosity|resp}}
{{var-short|Do not impose the conductivity sum rule in velocity gauge}}
{{var-usage|}}
<span id=MetDamp></span>
{{var-basic|MetDamp|None|Flag}}{{var-default|off}}{{var-verbosity|resp}}
{{var-short|Define \w+=sqrt(\w*(\w+i\eta))}}
{{var-usage|}}
<span id=Reflectivity></span>
{{var-basic|Reflectivity|None|Flag}}{{var-default|off}}{{var-verbosity|resp}}
{{var-short|Compute reflectivity at normal incidence}}
{{var-usage|}}
<span id=DrudeWBS></span>
{{var-basic|DrudeWBS|Energy|Complex}}{{var-verbosity|resp}}
{{var-short|Drude plasmon}}
{{var-usage|}}
<span id=BS_CPU></span>
{{var-basic|BS_CPU||}}{{var-verbosity|par}}
{{var-short| CPUs for each role}}
{{var-usage|}}
<span id=BS_ROLEs></span>
{{var-basic|BS_ROLEs||}}{{var-verbosity|par}}
{{var-short| CPUs for each role}}
{{var-usage|}}
<span id=BS_nCPU_LinAlg_INV></span>
{{var-basic|BS_nCPU_LinAlg_INV||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
<span id=BS_nCPU_LinAlg_DIAGO></span>
{{var-basic|BS_nCPU_LinAlg_DIAGO||}}{{var-verbosity|par}}
{{var-short|}}
{{var-usage|}}
===Bethe Salpeter Kernel===
<span id=bsk></span>
{{var-basic|bsk|None|String}}
{{var-short|Runlevel name: "Bethe Salpeter Equation kernel"}}
{{var-usage|Activate with -k <opt>}}
<span id=bss></span>
{{var-basic|bss|None|String}}
{{var-short|Runlevel name: "Bethe Salpeter Equation solver"}}
{{var-usage|Activate with -y <opt>}}
<span id=BSENGexx></span>
{{var-basic|BSENGexx|RL/Energy|Integer/Real}}
{{var-short|G-components to be summed in the Exchange part of the BSE kernel, which takes into account the Local-field effects}}
{{var-usage|Small values increase speed. Convergence tests are required.}}
<span id=BSENGBlk></span>
{{var-basic|BSENGBlk|RL/Energy|Integer/Real}}
{{var-short|Number of RL-components of the Screened Coulomb Potential matrix W(G,G'), to be included in the sum of the e-h attractive Kernel}}
{{var-usage|Try using the diagonal terms only first (BSresKmod BScplKmod variables); use a smaller number than the dimension of the Screened interaction matrix}}
<span id=WehCpl></span>
{{var-basic|WehCpl|None|Flag}}
{{var-short|activate W in the Coupling part}}
{{var-usage|}}
<span id=WehDiag></span>
{{var-basic|WehDiag|None|Flag}}
{{var-short|diagonal (G-space) the eh interaction}}
{{var-usage|}}
<span id=BSSmod></span>
{{var-basic|BSSmod|None|String}}
{{var-short|select solver for BSE}}
{{var-usage|(h)aydock/(d)iagonalization/(i)nversion/(t)ddft}}
<span id=BSHayTrs></span>
{{var-basic|BSHayTrs|None|Real}}{{var-default|-0.02}}
{{var-short|Threshold for accuracy of the iterative Haydock process}}
{{var-usage|Negative sign: average difference, over the energy range, of two consecutive approximations to the spectrum. Positive sign: maximum difference, over the energy range, of two consecutive approximations to the spectrum}}
<span id=BSSInvMode></span>
{{var-basic|BSSInvMode|None|String}}{{var-default|Off}}
{{var-short|select full or perturbative inversion solver for BSE}}
{{var-usage|(p) perturbative (f) full}}
<span id=BSEPSInvTrs></span>
{{var-basic|BSEPSInvTrs|None|Real}}{{var-default|0.01}}
{{var-short|Inversion treshold. }}
{{var-usage|Relative[o/o](>0)/Absolute(<0)}}
<span id=BSSInvPFratio></span>
{{var-basic|BSSInvPFratio|None|real}}
{{var-short|Inversion solver. Ratio between the number of frequencies solved pert/full}}
{{var-usage|}}
<span id=BSSInvKdiag></span>
{{var-basic|BSSInvKdiag|None|Flag}}
{{var-short|}}
{{var-usage|}}
<span id=BSSPertWidth ></span>
{{var-basic|BSSPertWidth |None|Flag}}
{{var-short|}}
{{var-usage|}}
<span id=WRbsWF></span>
{{var-basic|WRbsWF|None|Flag}}
{{var-short|}}
{{var-usage|}}


<span id="BSENGexx">
===Non-linear===
{{var3|BSENGexx|RL/Energy|Integer/Real|G-components to be summed in the Exchange part of the BSE kernel, which takes into account the Local-field effects|Small values increase speed. Convergence tests are required.}}
<span id=nloptics></span>
</span>
{{var-basic|nloptics||String}}
<span id="BSENGBlk">
{{var-short|Runlevel name}}
{{var3|BSENGBlk|RL/Energy|Integer/Real|Number of RL-components of the Screened Coulomb Potential matrix W(G,G'), to be included in the sum of the e-h attractive Kernel | Try using the diagonal terms only first (BSresKmod BScplKmod variables); use a smaller number than the dimension of the Screened interaction matrix
{{var-usage|}}
}}
<span id=NLBands></span>
</span>
{{var-basic|NLBands||}}{{var-default|From ns.ndb1}}
<span id="BSEBands">
{{var-short|Number of bands}}
{{var3|BSEBands|None|Integer Range| Bands range: Specifies the band states from which the electron-hole basis of the BSE kernel is constructed | Choose few bands close to the Fermi level. 
{{var-usage|}}
}}
<span id=NLverbosity></span>
</span>
{{var-basic|NLverbosity||String}}{{var-default|low}}
<span id="KfnQP_E">
{{var-short|Verbosity level "high" or "low"}}
{{var3|KfnQP_E|eV/None/None|Scissors| QP corrections using a scissor operator and valence/conduction stretching.  | From a previous GW calculation or experiment. 
{{var-usage|}}
}}
<span id=NLstep></span>
</span>
{{var-basic|NLstep|fs|Real}}{{var-default|0.01}}
{{var-short|Time step}}
{{var-usage|}}
<span id=NLtime></span>
{{var-basic|NLtime|fs|Real}}{{var-default|-1}}
{{var-short|Simulaiton length}}
{{var-usage|If negative automatically set the right value for SHG}}
::This value is invertionaly proportional to NLDamping
<span id=NLintegrator></span>
{{var-basic|NLintegrator||String}}{{var-default|INVINT}}
{{var-short|Integrator}}
{{var-usage|}}
<span id=NLCorrelation ></span>
{{var-basic|NLCorrelation ||String}}{{var-default|IPA (independent particle approximation)}}
{{var-short|Correlation level}}
{{var-usage|}}
<span id=NLDamping></span>
{{var-basic|NLDamping|eV|Real}}{{var-default|0.2}}
{{var-short|Damping (or dephasing)}}
{{var-usage|}}
<span id=EvalCurrent></span>
{{var-basic|EvalCurrent||Flag}}{{var-default|Off}}
{{var-short|}}
{{var-usage|Calculate the current if true}}
<span id=HARRLvcs></span>
{{var-basic|HARRLvcs||Integer}}{{var-default|from ns.ndb1}}
{{var-short|Number of G-vectors in the Hartree}}
{{var-usage|}}
<span id=EXXRLvcs></span>
{{var-basic|EXXRLvcs||Integer}}{{var-default|from Collisions}}
{{var-short|Number of G-vectors in the Screened Exchange}}
{{var-usage|}}
<span id=ExtF_Dir></span>
{{var-basic|ExtF_Dir|None|Vector}}{{var-default|(1,0,0)}}
{{var-short|Direction of the external field}}
{{var-usage|}}
<span id=ExtF_kind></span>
{{var-basic|ExtF_kind||String}}{{var-default|SOFTSIN}}
{{var-short|Field kind}}
{{var-usage|Type of external field, for non-linear response only SIN or SOFTSIN}}
<span id=NLLrcAlpha></span>
{{var-basic|NLLrcAlpha||Real}}{{var-verbosity|nl}}
{{var-short|Long range alpha correction}}
{{var-usage|}}
<span id=UseDipoles></span>
{{var-basic|UseDipoles||Flag}}{{var-default|Off}}{{var-verbosity|nl}}
{{var-short|Use Covariant Dipoles (just for test purpose)}}
{{var-usage|}}
<span id=FrSndOrd></span>
{{var-basic|FrSndOrd||Flag}}{{var-default|Off}}
{{var-short|Force second order numerical derivatives (only for testing purpose)}}
{{var-usage|}}

Latest revision as of 12:22, 11 June 2021

This page gives a brief explanation of the many input variables used by Yambo.
Variables apply to the standard yambo executable unless indicated otherwise.
Default values are read from the indicated database file unless stated otherwise.
Required verbosity flags are indicated where appropriate.

Units can have the following values:

  • None = no unit
  • RL = number of G-vectors
  • Energy = Ha, mHa (Hartree atomic units), Ry, mRy (Rydberg atomic units), eV, meV (electron volts), K, THz, GHz
  • Length = Bohr atomic units a.u.

Formats are described on the Format page.

DO NOT EDIT THIS PAGE DIRECTLY!!! CHANGES WILL BE LOST!!!



All Variables (alphabetical order)

BDmRange BEnRange BEnSteps BLongDir BndsRnXd BndsRnXp BoseCut BoseTemp
BS_CPU BS_nCPU_LinAlg_DIAGO BS_nCPU_LinAlg_INV BS_ROLEs bse BSEBands BSEmod BSENGBlk
BSENGexx BSEPSInvTrs BSHayTrs bsk BSKmod bss BSSInvKdiag BSSInvMode
BSSInvPFratio BSSmod BSSPertWidth CGrdSpXd chi ChiLinAlgMod Chimod cohsex
CUTBox CUTCol_test CUTCylLen CUTGeo CUTRadius CUTwsGvec DbGdQsize DbGdQsize
DBsFRAGpm DBsIOoff DIP_Threads DipApproach DipApproach DipPDirect DipPDirect DmERefXd
DmRngeXd DmRngeXp DrClassic DrudeWBS DrudeWXd dScStep DysSolver EhEngyXd
ElecTemp Em1Anys em1d em1s EMStpsXd EnRngeXd EnRngeXp ETStpsXd
ETStpsXp EvalCurrent ExtendOut ExtF_Dir ExtF_kind EXXRLvcs EXXRLvcs FFTGvecs
FrSndOrd FxcGRLc Gauge GbndRnge GDamping GDmRnge GEnRnge GEnSteps
GfnQP_E GfnQP_N GfnQP_Wc GfnQP_Wc_dos GfnQP_Wc_E GfnQP_Wv GfnQP_Wv_dos GfnQP_Wv_E
GfnQP_Z GfnQPdb GrFnTpXd GTermEn GTermKind gw0 HARRLvcs HF_and_locXC
IDEm1Ref IkSigLim IkXLim K_Threads KfnQP_E KfnQP_N KfnQP_Wc KfnQP_Wc_dos
KfnQP_Wc_E KfnQP_Wv KfnQP_Wv_dos KfnQP_Wv_E KfnQP_Z KfnQPdb life LifeTrCG
LongDrXd LongDrXp LRC_alpha MaxGvecs MEM_tresh MetDamp Nelectro NewtDchk
NGsBlkXd NLBands NLCorrelation NLDamping NLintegrator NLLrcAlpha NLogCPUs nloptics
NLstep NLtime NLverbosity NoCondSumRule NonPDirs OccTresh OnMassShell optics
PAR_def_mode PAR_def_mode PPAPntXp Qdirection QPerange QPerange QpgFull QPkrange
QPkrange QpntsRXd QptCoord QShiftOrder RandGvec RandQpts Reflectivity rim_cut
SE_CPU SE_ROLEs SE_Threads setup ShiftedPaths ShiftedPaths StdoHash tddft
UseDipoles UseNLCC VXCRLvcs WehCpl WehDiag WFbuffIO WRbsWF X_all_q_CPU
X_all_q_nCPU_LinAlg_INV X_all_q_ROLEs X_finite_q_CPU X_finite_q_nCPU_LinAlg_INV X_finite_q_ROLEs X_q_0_CPU X_q_0_nCPU_LinAlg_INV X_q_0_ROLEs
X_Threads XfnQP_E XfnQP_N XfnQP_Wc XfnQP_Wc_dos XfnQP_Wc_E XfnQP_Wv XfnQP_Wv_dos
XfnQP_Wv_E XfnQP_Z XfnQPdb

Global options

Nelectro (Units: None, Format: Real)Default: From ns.db1 Verbosity: -V gen
Meaning: Number of electrons
Usage: Change to shift the Fermi level by hand.

ElecTemp (Units: Energy, Format: Real)Default: 0.000 Verbosity: -V gen
Meaning: Electronic Temperature
Usage:

BoseTemp (Units: Energy, Format: Real)Default: -1 Verbosity: -V gen
Meaning: Bosonic Temperature
Usage:

OccTresh (Units: None, Format: Real)Default: 1.00E-05 Verbosity: -V gen
Meaning: Occupation treshold (metallic bands)
Usage:

StdoHash (Units: None, Format: Integer)Default: 40 Verbosity: -V io
Meaning: Number of hashes in live-timing output.
Usage: Might be useful to increase for very long jobs, or if the code is hanging.

DBsIOoff (Units: None, Format: String)Default: none Verbosity: -V io
Meaning: List of databases not written to disk
Usage: Space-separated list of DB with NO I/O. DB is (DIP,X,HF,COLLs,J,GF,CARRIERs,OBS,W,SC,BS,ALL). No ndb.* file is written.
Example: DBsIOoff= "DIP" means ndb.dip_iR_and_P_fragment_* is not written, but stored in memory if Yambo needs it.

DBsFRAGpm (Units: None, Format: String)Default: none Verbosity: -V io
Meaning: List of databases to be fragmented
Usage: Space-separated list of +DB to FRAG and -DB to NOT FRAG, where DB is (DIP,X,W,HF,COLLS,K,BS,QINDX,RT,ELP. Fragments the database. Smaller files (e.g. ndb.em1s_fragment_*) are created instead of a large one (e.g. ndb.em1s). Faster read/write operations in parallel runs

WFbuffIO (Units: None, Format: Flag)Default: Off Verbosity: -V io
Meaning: Wave-functions buffered I/O
Usage: Parts of the WFs are stored by the node. Nodes communicate when these elements are needed. Memory heavy.

MEM_tresh (Units: Kb, Format: Integer)Default: 10000 Verbosity: -V gen
Meaning: Threshold on traced memory allocations/deallocations
Usage:

NLogCPUs (Units: None, Format: Integer) Verbosity: -V par
Meaning: Live-timing CPU`s (0 for all)
Usage: Number of CPUs that write a LOG file. 0 means all CPUs.

PAR_def_mode (Units: None, Format: String)Default: balanced Verbosity: -V par
Meaning: Parallelization mode ("balanced"/"memory"/"workload")
Usage: You can set "memory" to save memory

FFTGvecs (Units: RL/Energy, Format: Integer/Real) Verbosity: -V RL
Meaning: Number of G-vectors or energy cut off for expanding the wavefunctions/FFT transforms
Usage: Determines size (memory) of calculation. Corresponds to cutoff in DFT calculation; can be much less than geometry cutoff. It needs careful convergence.

Initialization

setup (Units: None, Format: String)
Meaning: Runlevel name
Usage: Activate with -i option

MaxGvecs (Units: RL/Energy, Format: Integer/Real) Verbosity: -V RL
Meaning: Maximum number of G-vectors that can be used by code
Usage:

IkSigLim (Units: Range, Format: Integer ) Verbosity: -V kpt
Meaning: QP K-points indices range
Usage:

IkXLim (Units: , Format: ) Verbosity: -V kpt
Meaning:
Usage:

QptCoord (Units: , Format: ) Verbosity: -V kpt
Meaning:
Usage:

Random integration method and cutoff Coulomb potentials

rim_cut (Units: None, Format: String)
Meaning: Runlevel name
Usage: Activate with -r option

RandQpts (Units: RL, Format: Integer)
Meaning: Number of random q-points in the BZ to perform Monte Carlo Integration,
Usage: It needs convergence: values like 10^6 can be used to ensure convergence. Needed for non 3D system to avoid divergences for small q, and needed to build cutoff potential with box shape See also: RandGvec

CUTGeo (Units: None, Format: String)Default: none
Meaning: Cutoff geometry
Usage: Allowed values are: "box/cylinder/sphere/ws X/Y/Z/XY...", e.g. "box xy" or "cylinder y". WS is the suggested option for orthorhombic cells. Use sphere (0D) for molecules, cylinder (1D) for polymers and nanotubes, box (0D, 1D, 2D) for all geometries. XYZ: cut in all directions. Box: XY: cut in XY only. Cylinder X/Y/Z indicates cylinder axis. When using Box shapes, the RIM is also needed to calculate the potential. In Box for large enough boxes assigns Box side slighlty smaller than the cell box. In order to use the box a previous RandQpts (rim_cut) is needed. See also: CUTBoxCUTRadiusCUTCylLenCUTwsGvec

CUTBox (Units: Length, Format: Vector)Default: (0,0,0)
Meaning: Dimensions of box
Usage: {{{1}}}

CUTRadius (Units: Length, Format: Real)
Meaning: Sphere/cylinder radius.
Usage: Cutoff radius used in spehere and cylinder geometry

CUTCylLen (Units: Length, Format: Real)
Meaning: Length for finite Cylinders
Usage: {{{1}}}

CUTwsGvec (Units: Energy, Format: Real)Default: 0.7
Meaning: Energy cut off on modified component
Usage: {{{1}}} See also: CUTGeo

RandGvec (Units: Energy, Format: ) Verbosity: -V RL
Meaning: Number of G vectors the RIM is calculated at
Usage: {{{1}}}

QpgFull (Units: None, Format: Flag)Default: off Verbosity: -V RL
Meaning:
Usage: Monte Carlo random integratio for the full coulomb matrix 1/

Em1Anys (Units: , Format: ) Verbosity: -V RL
Meaning:
Usage:

IDEm1Ref (Units: , Format: ) Verbosity: -V RL
Meaning:
Usage:

CUTCol_test (Units: None, Format: Flag)Default: off Verbosity: -V RL
Meaning: Provides in output the truncated Coulomb potential in real space
Usage: Useful option for debugging purposes.

Hartree-Fock Self-energy and Vxc

HF_and_locXC (Units: None, Format: String)
Meaning: Runlevel name
Usage: Activate with -x

EXXRLvcs (Units: RL/Energy, Format: Integer/Real)Default: MaXGvecs
Meaning: Number of G-vectors used in the sum of the exchange self-energy Sx.
Usage: It needs careful convergence. As it is not particularly time consuming, large values can be used to ensure convergence. Generally a large number is needed as the QP energies show a slow convergence. The calcualtion of the exchange part is rather fast.

VXCRLvcs (Units: RL/Energy, Format: Integer/Real)Default: MaXGvecs
Meaning: Number of G-vectors used in the evaluation of the density for the <Vxc> matrix element
Usage: A large number is needed in order to have a precise cancellation with the ground state calculation, in particular when GGA potential are used. A good measure of the accuracy is to compare the E_xc value printed in Yambo report and QE output file.

QPkrange (Units: None, Format: Range)Default: All qp and all bands available.
Meaning: Range of states (n,k) where GW/Sx elements are calculated
Usage: Careful use of fewer k-points and bands reduces the calculation time; yambo will interpolate the rest. Format is: first k-point See also: QPerange

UseNLCC (Units: None, Format: Flag)Default: off Verbosity: -V qp
Meaning: If present, add NLCC contributions to the charge density.
Usage: Care is needed. Beware NLCC are included in the Vxc but not in the exchange part of the self energy that could be inconsistent. Suggestion: if possible use PP without NLCC.

QPerange (Units: None/Energy, Format: Range) Verbosity: -V qp
Meaning: Range of states (E,k) where GW/Sx elements are calculated
Usage: Careful use of fewer k-points and bands reduces the calculation time; yambo will interpolate the rest. Format is: first k-point See also: QPkrange

SE_CPU (Units: None, Format: String) Verbosity: -V par
Meaning: CPUs for each role
Usage: For consistency the product of the CPUs for each role has to be equal to the number of MPI tasks of the job

SE_ROLEs (Units: None, Format: String) Verbosity: -V par
Meaning: CPUs roles (q,qp,b)
Usage: {{{1}}} See also: SE_ROLEs

SE_Threads (Units: None, Format: Integer) Verbosity: -V par
Meaning: Number of threads for self-energy
Usage: Very efficient. To be effective the code should have been compiled with OMP support.

GW

cohsex (Units: None, Format: String)
Meaning: Runlevel name
Usage:

gw0 (Units: None, Format: String)
Meaning: Runlevel name
Usage: Activate with -g <opt>

life (Units: None, Format: String)
Meaning: Runlevel name
Usage: Activate with -l option.

QPkrange (Units: None, Format: Range)Default: From ns.db1 (all k-points, all bands)
Meaning: K-points and band range where you want to calculate the GW correction.
Usage: If interested in non consecutive kpoints or bands multiple rows can be also considered. The syntax is first kpoint

GbndRnge (Units: None, Format: Range)
Meaning: Specifies the range of bands entering in the sum over states in the correlation part of the self energy
Usage: It needs several empty states. Single quasiparticle states converges very slowly with respect GbndRnge, energy differences (e.g. gaps) behave better. See also GTermKind variable in order to speed up the convergences.This number is usually larger than the number of bands used to calculated the dielectricconstant. Single quasiparticle energies converge slowly with respect GbndRnge, energy difference behave better. You can use terminator technique to mitigate the slow dependence.

GDamping (Units: , Format: )
Meaning: Small damping in the Green's function definition, the delta parameter.
Usage: The final result shouuld not depend on that, usually set at 0.1 eV

dScStep (Units: Energy, Format: Real)Default: 0.1
Meaning: Energy step to evaluate Z factors
Usage:

DysSolver (Units: , Format: )
Meaning: Indicates method used to solve the Dyson equation
Usage: "n" Newton linearization (First order expansion around KS eigenvalue), 's' non linear iterative secant method

LifeTrCG (Units: None, Format: Real)Default: 100
Meaning: Lifetime transition reduction (%)
Usage:

GfnQPdb See KfnQPdb

GfnQP_N See KfnQP_N

GfnQP_E See KfnQP_E

GfnQP_Z See KfnQP_Z

GfnQP_Wv_E See KfnQP_Wv_E

GfnQP_Wv See KfnQP_Wv

GfnQP_Wv_dos See KfnQP_Wv_dos

GfnQP_Wc_E See KfnQP_Wc_E

GfnQP_Wc See KfnQP_Wc

GfnQP_Wc_dos See KfnQP_Wc_dos

GTermKind (Units: None, Format: String) Verbosity: -V qp
Meaning: Type of terminator to accelarate onvergence with respect empty states
Usage: Default is "none", possible options are "BG" for the Bruneval-Gonze terminator. See BG[1]. It speeds up the convergence with respect to number of empty bands.

GTermEn (Units: Energy, Format: ) Verbosity: -V qp
Meaning: Energy of the fictitious pole of the terminator
Usage:

NewtDchk (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

ExtendOut (Units: None, Format: Flag) Verbosity: -V qp
Meaning: Extended output: Print more quantities in qp output files
Usage:

OnMassShell (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

QPerange (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

GEnSteps (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage: -g s

GEnRnge (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage: -g s

GDmRnge (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage: -g s

Screening

em1d (Units: , Format: String)
Meaning: Runlevel name
Usage:

em1s (Units: , Format: String)
Meaning: Runlevel name
Usage:

NGsBlkXd (Units: RL/Energy, Format: Integer/Real)
Meaning: Number of G-vectors or energy cut off in the screening (response block size)
Usage: Determines the size of the dielectric matrix in G-space. Needed for inclusion of local field effects, it should be much smaller than the number of G-vectors needed to expand the wavefunctions (FFTGvecs). It needs careful convergence, and should be converged along with BndsRnXd. Depends strongly on the system inhomogeneity. See also: BndsRnXpFFTGvecs

PPAPntXp (Units: Energy, Format: Real)Default: 1 Ha (27.2114eV)
Meaning: Plasmon pole Imaginary Energy
Usage: The self energy in the imaginary axis should be a smooth function so it should not have a strong dependence on this pole energy. Set it at an higher value of the plasmon energy (see EELS spectrum). this is the second frequency used to fit the Godby-Needs plasmon-pole model (PPM). If results depend consistently by changing this frequency, the PPM is not adequate for your calculation and it is need to gp beyond that, e.g. Real-axis.

BndsRnXp See BndsRnXd

EnRngeXp See EnRngeXd

DmRngeXp See DmRngeXd

ETStpsXp See ETStpsXd

LongDrXp See LongDrXd

Optics/chi in G-space

optics (Units: None, Format: String)
Meaning: Runlevel name: "Optics"
Usage: Activate with -o <opt>. Optics runlevel.

chi (Units: None, Format: String)
Meaning: Runlevel name: "Dyson equation for chi."
Usage: Activate with -o c. Dyson equation for chi.

tddft (Units: None, Format: String)
Meaning: Runlevel name: "Use TDDFT kernel"
Usage: Activate with -k alda or -k lrc. Use TDDFT kernel

Chimod (Units: None, Format: String)
Meaning: Type of kernel in TDDFT Dyson equation
Usage: Do not set this manually - set using the appropriate -k command line option. Allowed values: IP/Hartree/ALDA/LRC/BSfxc. IP indicates no kernel (independent particle level/RPA without local fields)

X_Threads (Units: None, Format: Integer)
Meaning: Number of threads for response functions
Usage: efficient, need extra mem

DIP_Threads (Units: , Format: )
Meaning:
Usage:

QpntsRXd (Units: None, Format: Range)
Meaning: Range of indexes of q-points/transferred momenta to be computed.
Usage: Set to 1 1 to select just the long wavelength term. Range from 1:nqpt.

BndsRnXd (Units: None, Format: Range)
Meaning: Bands range: Specifies the number of bands entering in the sum over states in the RPA response function
Usage: It needs several empty states. See also GTermKind variable in order to speed up the convergences. Reduce range in order to lower memory. In metals it includes partially filled bands. See also EhEngyXd. See also: GTermKind

EnRngeXd (Units: Energy, Format: Range)
Meaning: Energy range the spectrum is calculated across.
Usage: Extremae of the energy range across which optical spectra will be computed. See also: EhEngyXd

DmRngeXd (Units: Energy, Format: Range)
Meaning: Determines the damping used across the requested spectral range.
Usage: Typically this is kept constant. If different values are used, the damping at each energy will be interpolated linearly. This can be useful when poor k-point sampling leads to large oscillations at higher energy.

ETStpsXd (Units: None, Format: Integer)
Meaning: Number of energy steps in computing X
Usage: Determines the number of steps in energy the response function/spectrum is computed for in the desired range defined by EnRngeXd. In the case of a full frequency GW the range is fixed by the occupied/empty states included in the calculation, the number of frequency requires a careful check

LongDrXd (Units: Length, Format: Vector)
Meaning: Electric field direction
Usage: Pay attention how the system is oriented when treating non 3D systems and choose a direction in the plane/axis where your system lies

FxcGRLc (Units: , Format: )
Meaning: XC-kernel size
Usage: Needs convergence study. Much less than FFTGvecs

LRC_alpha (Units: None, Format: Real)Default: 0.00
Meaning: LRC fitting parameter alpha
Usage: Long-range tail of the fxc kernel. Depends on the system: the larger the screening the smaller this parameter.

XfnQPdb See KfnQPdb

XfnQP_N See KfnQP_N

XfnQP_E See KfnQP_E

XfnQP_Z See KfnQP_Z

XfnQP_Wv_E See KfnQP_Wv_E

XfnQP_Wv See KfnQP_Wv

XfnQP_Wv_dos See KfnQP_Wv_dos

XfnQP_Wc_E See KfnQP_Wc_E

XfnQP_Wc See KfnQP_Wc

XfnQP_Wc_dos See KfnQP_Wc_dos

NonPDirs (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

ChiLinAlgMod (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

GrFnTpXd (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage: {{{1}}}

DmERefXd (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

CGrdSpXd (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

EMStpsXd (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

DrudeWXd (Units: Energy, Format: Complex) Verbosity: -V resp
Meaning: Drude plasmon energy and inverse lifetime.
Usage:

EhEngyXd (Units: Energy, Format: Range)Default: (-1,-1) Verbosity: -V resp
Meaning: Electron-hole energy range
Usage: An alternative way to BndsRnXd to restrict transitions, but will not reduce memory

DrClassic (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

DipApproach (Units: , Format: String)Default: G-space v Verbosity: -V resp
Meaning: Different ways to calculate dipole matrix elements
Usage:

DipPDirect (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

ShiftedPaths (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

Qdirection (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

QShiftOrder (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

DbGdQsize (Units: , Format: ) Verbosity: -V resp
Meaning:
Usage:

PAR_def_mode (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

X_q_0_CPU (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

X_q_0_ROLEs (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

X_q_0_nCPU_LinAlg_INV (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

X_finite_q_CPU (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

X_finite_q_ROLEs (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

X_finite_q_nCPU_LinAlg_INV (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

X_all_q_CPU (Units: , Format: )
Meaning: CPUs for each role
Usage:

X_all_q_ROLEs (Units: , Format: )
Meaning: CPUs roles (q,k,c,v)
Usage: MPI-c,v best memory distribution. MPI-k efficient, some memory replication. MPI-q may lead to load unbalance.

X_all_q_nCPU_LinAlg_INV (Units: , Format: )
Meaning: CPUs for matrix inv
Usage:

Optics/BSE in eh-space

bse (Units: None, Format: String)
Meaning: Runlevel name: "Bethe Salpeter Equation"
Usage: Activate with -o b

K_Threads (Units: None, Format: Integer)
Meaning: Number of threads for response functions
Usage:

BSEmod (Units: None, Format: String)Default: retarded
Meaning:
Usage: resonant/retarded/coupling

BSKmod (Units: None, Format: String)Default: IP
Meaning: Bethe Salpeter kernel
Usage: Do not set this manually: activate with the appropriate -k <opt> command line option, where opt is one of IP/Hartree/HF/ALDA/SEX.

BEnRange (Units: Energy, Format: Range)Default: [0:10] eV
Meaning: Energy range for computing the macroscopic dielectric function using BSE
Usage:

BDmRange (Units: Energy, Format: Range)Default: (0.10000 , 0.10000)
Meaning: Broadening for the BSE calculation
Usage: Lorentzian broadening changes linearly between the two values

BEnSteps (Units: None, Format: Integer)Default: 100
Meaning: Number of evenly spaced energy points in spectrum
Usage:

BLongDir (Units: None, Format: Vector)Default: (1,0,0)
Meaning: Direction of the longitudinal perturbation
Usage:

BSEBands (Units: None, Format: Range)Default: All bands
Meaning: Bands range: Specifies the band states from which the electron-hole basis of the BSE kernel is constructed
Usage: Choose few bands close to the Fermi level. Size scales rapidly with the number of bands: BSE is rewritten as an eigenvalue problem for the 2 particle Hamiltonian: size of matrix [Nv x Nc x NKBZ ] x [Nv x Nc x NKBZ]

KfnQPdb (Units: None, Format: String) Verbosity: -V qp
Meaning: Database for QP corrections.
Usage: From a previous GW calculation. An interpolation of the missing QP-values on the basis of the QP-database is available See also: KfnQP_E
Format: "<what> < <path>/ndb.QP" with <what> = E,W,Z for QP energy correction, QP width and renormalization factor. For example, from a previous GW calculation use KfnQPdb= "E < ./SAVE/ndb.QP"

KfnQP_N (Units: None, Format: Integer) Verbosity: -V qp
Meaning: Interpolation neighbours?
Usage:

KfnQP_E (Units: eV/None/None, Format: Scissors) Verbosity: -V qp
Meaning: QP corrections using a scissor operator and stretching coefficients for the conduction/valence bandwidths.
Usage: Insert values from a previous GW calculation or experiment. This is a lighter way to include GW corrections than KfnQP_E. Format is: scissor See also: KfnQPdb

KfnQP_Z (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

KfnQP_Wv_E (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

KfnQP_Wv (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

KfnQP_Wv_dos (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

KfnQP_Wc_E (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

KfnQP_Wc (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

KfnQP_Wc_dos (Units: , Format: ) Verbosity: -V qp
Meaning:
Usage:

BoseCut (Units: , Format: ) Verbosity: -V gen
Meaning:
Usage:

DbGdQsize (Units: None, Format: Real) Verbosity: -V resp
Meaning: Percentual of the total DbGd transitions to be used
Usage:

DipApproach (Units: None, Format: String)Default: G-space v Verbosity: -V resp
Meaning: how dipoles are calculated:G-space v
Usage: Options are: G-space v/R-space x/Covariant/Shifted grids

DipPDirect (Units: None, Format: Flag)Default: off Verbosity: -V resp
Meaning: Directly compute <v> also when using other approaches for dipoles
Usage:

ShiftedPaths (Units: None, Format: String) Verbosity: -V resp
Meaning: Shifted grids paths (separated by a space)
Usage:

Gauge (Units: None, Format: String)Default: length Verbosity: -V resp
Meaning: Switch between lenght or velocity gauge
Usage:

NoCondSumRule (Units: None, Format: Flag)Default: off Verbosity: -V resp
Meaning: Do not impose the conductivity sum rule in velocity gauge
Usage:

MetDamp (Units: None, Format: Flag)Default: off Verbosity: -V resp
Meaning: {{{1}}}
Usage:

Reflectivity (Units: None, Format: Flag)Default: off Verbosity: -V resp
Meaning: Compute reflectivity at normal incidence
Usage:

DrudeWBS (Units: Energy, Format: Complex) Verbosity: -V resp
Meaning: Drude plasmon
Usage:

BS_CPU (Units: , Format: ) Verbosity: -V par
Meaning: CPUs for each role
Usage:

BS_ROLEs (Units: , Format: ) Verbosity: -V par
Meaning: CPUs for each role
Usage:

BS_nCPU_LinAlg_INV (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

BS_nCPU_LinAlg_DIAGO (Units: , Format: ) Verbosity: -V par
Meaning:
Usage:

Bethe Salpeter Kernel

bsk (Units: None, Format: String)
Meaning: Runlevel name: "Bethe Salpeter Equation kernel"
Usage: Activate with -k <opt>

bss (Units: None, Format: String)
Meaning: Runlevel name: "Bethe Salpeter Equation solver"
Usage: Activate with -y <opt>

BSENGexx (Units: RL/Energy, Format: Integer/Real)
Meaning: G-components to be summed in the Exchange part of the BSE kernel, which takes into account the Local-field effects
Usage: Small values increase speed. Convergence tests are required.

BSENGBlk (Units: RL/Energy, Format: Integer/Real)
Meaning: Number of RL-components of the Screened Coulomb Potential matrix W(G,G'), to be included in the sum of the e-h attractive Kernel
Usage: Try using the diagonal terms only first (BSresKmod BScplKmod variables); use a smaller number than the dimension of the Screened interaction matrix

WehCpl (Units: None, Format: Flag)
Meaning: activate W in the Coupling part
Usage:

WehDiag (Units: None, Format: Flag)
Meaning: diagonal (G-space) the eh interaction
Usage:

BSSmod (Units: None, Format: String)
Meaning: select solver for BSE
Usage: (h)aydock/(d)iagonalization/(i)nversion/(t)ddft

BSHayTrs (Units: None, Format: Real)Default: -0.02
Meaning: Threshold for accuracy of the iterative Haydock process
Usage: Negative sign: average difference, over the energy range, of two consecutive approximations to the spectrum. Positive sign: maximum difference, over the energy range, of two consecutive approximations to the spectrum

BSSInvMode (Units: None, Format: String)Default: Off
Meaning: select full or perturbative inversion solver for BSE
Usage: (p) perturbative (f) full

BSEPSInvTrs (Units: None, Format: Real)Default: 0.01
Meaning: Inversion treshold.
Usage: Relative[o/o](>0)/Absolute(<0)

BSSInvPFratio (Units: None, Format: real)
Meaning: Inversion solver. Ratio between the number of frequencies solved pert/full
Usage:

BSSInvKdiag (Units: None, Format: Flag)
Meaning:
Usage:

BSSPertWidth (Units: None, Format: Flag)
Meaning:
Usage:

WRbsWF (Units: None, Format: Flag)
Meaning:
Usage:

Non-linear

nloptics (Units: , Format: String)
Meaning: Runlevel name
Usage:

NLBands (Units: , Format: )Default: From ns.ndb1
Meaning: Number of bands
Usage:

NLverbosity (Units: , Format: String)Default: low
Meaning: Verbosity level "high" or "low"
Usage:

NLstep (Units: fs, Format: Real)Default: 0.01
Meaning: Time step
Usage:

NLtime (Units: fs, Format: Real)Default: -1
Meaning: Simulaiton length
Usage: If negative automatically set the right value for SHG
This value is invertionaly proportional to NLDamping

NLintegrator (Units: , Format: String)Default: INVINT
Meaning: Integrator
Usage:

NLCorrelation (Units: , Format: String)Default: IPA (independent particle approximation)
Meaning: Correlation level
Usage:

NLDamping (Units: eV, Format: Real)Default: 0.2
Meaning: Damping (or dephasing)
Usage:

EvalCurrent (Units: , Format: Flag)Default: Off
Meaning:
Usage: Calculate the current if true

HARRLvcs (Units: , Format: Integer)Default: from ns.ndb1
Meaning: Number of G-vectors in the Hartree
Usage:

EXXRLvcs (Units: , Format: Integer)Default: from Collisions
Meaning: Number of G-vectors in the Screened Exchange
Usage:

ExtF_Dir (Units: None, Format: Vector)Default: (1,0,0)
Meaning: Direction of the external field
Usage:

ExtF_kind (Units: , Format: String)Default: SOFTSIN
Meaning: Field kind
Usage: Type of external field, for non-linear response only SIN or SOFTSIN

NLLrcAlpha (Units: , Format: Real) Verbosity: -V nl
Meaning: Long range alpha correction
Usage:

UseDipoles (Units: , Format: Flag)Default: Off Verbosity: -V nl
Meaning: Use Covariant Dipoles (just for test purpose)
Usage:

FrSndOrd (Units: , Format: Flag)Default: Off
Meaning: Force second order numerical derivatives (only for testing purpose)
Usage:
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