Variables
This page gives a brief explanation of the format and meaning for input variables used by Yambo. Check the Units and Format pages for accepted values of each.
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 BSEEhEny BSEmod
BSENGBlk BSENGexx BSEPSInvTrs BSHayTrs bsk BSKmod BSSInvMode BSSInvPFratio
BSSmod 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 ExtendOut
EXXRLvcs FFTGvecs 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 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 LifeTrCG LongDrXd LongDrXp
LRC_alpha MaxGvecs MEM_tresh MetDamp Nelectro NewtDchk NGBlkXd NLogCPUs
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 UseNLCC VXCRLvcs WehCpl WFbuffIO
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
StdoHash(Units: , Format: Integer)Default: 40 Verbosity:-V io- Meaning: Number of hashes in live-timing output
- Usage:
DBsIOoff(Units: , Format: String) 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)
DBsFRAGpm(Units: , Format: String) 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
MEM_tresh(Units: , Format: ) Verbosity:-V gen- Meaning: Threshold on traced memory allocations/deallocations
- Usage:
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: It needs careful convergence. Determines the memory needed.
Initialization
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:
Random integration method and cutoff
RandQpts(Units: RL, Format: Integer)- Meaning: Number of random q-points in the BZ
- Usage: It needs convergence: values like 10^6 can be used to ensure convergence. See also:
RandGvec
CUTGeo(Units: None, Format: String)- Meaning: Cutoff geometry
- Usage: Allowed values are: "box/cylinder/sphere X/Y/Z/XY...", e.g. "box xy" or "cylinder y".
Hartree-Fock Self-energy and Vxc
EXXRLvcs(Units: RL/Energy, Format: Integer/Real)- Meaning: Number of G-vectors used in the sum of the exchange self-energy Sx.
- Usage: It needs careful convergence: not particularly time consuming, large values can be used to ensure convergence.
GW
QPkrange(Units: None, Format: Range)- Meaning: First and last Indexes of kpoints and bands the self energy correction is calculated
- Usage: If interested in non consecutive kpoints or bands multiple rows can be also considered
GbndRnge(Units: None, Format: Range)- Meaning: Bands range: Specifies the number 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.
GfnQPdbSeeXfnQPdb
GfnQP_NSeeXfnQP_N
GfnQP_ESeeXfnQP_E
GfnQP_ZSeeXfnQP_Z
GfnQP_Wv_ESeeXfnQP_Wv_E
GfnQP_WvSeeXfnQP_Wv
GfnQP_Wv_dosSeeXfnQP_Wv_dos
GfnQP_Wc_ESeeXfnQP_Wc_E
GfnQP_WcSeeXfnQP_Wc
GfnQP_Wc_dosSeeXfnQP_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]
ExtendOut(Units: None, Format: Flag) Verbosity:-V qp- Meaning: Extended output: Print more quantities in qp output files
- Usage: Optional variable (-V qp). Uncomment to activate
Screening
NGBlkXd(Units: RL/Energy, Format: Integer/Real)- Meaning: Number of G-vectors or energy cut off in the screening.
- 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. It needs careful convergence.
PPAPntXp(Units: Energy, Format: Real)- Meaning: Plasmon pole Imaginary Energy (Default 1 Ha)
- 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)
BndsRnXpSeeBndsRnXd
EnRngeXpSeeEnRngeXd
DmRngeXpSeeDmRngeXd
ETStpsXpSeeETStpsXd
LongDrXpSeeLongDrXd
Optics/chi in G-space
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)
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.
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. 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.
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
XfnQPdb(Units: , Format: ) Verbosity:-V qp- Meaning:
- Usage:
- Format: "<what> < <path>/ndb.QP" with <what> = E,W,Z for QP energy correction, QP width and renormalization factor.
DrudeWXd(Units: Energy, Format: Complex) Verbosity:-V resp- Meaning: Drude plasmon energy and inverse lifetime.
- Usage:
Optics/BSE in eh-space
BSEBands(Units: None, Format: Range)- 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.
KfnQPdbSeeXfnQPdb
KfnQP_NSeeXfnQP_N
KfnQP_ESeeXfnQP_E
KfnQP_ZSeeXfnQP_Z
KfnQP_Wv_ESeeXfnQP_Wv_E
KfnQP_WvSeeXfnQP_Wv
KfnQP_Wv_dosSeeXfnQP_Wv_dos
KfnQP_Wc_ESeeXfnQP_Wc_E
KfnQP_WcSeeXfnQP_Wc
KfnQP_Wc_dosSeeXfnQP_Wc_dos
Bethe Salpeter/TDDFT Kernel
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