Input file generation: Difference between revisions
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* The <code>yambo</code> executable | * The <code>yambo</code> executable | ||
== | == Input file generator == | ||
First, move to the appropriate folder and initialize the Yambo databases if you haven't already done so. | |||
$ cd YAMBO_TUTORIALS/hBN/YAMBO | |||
$ yambo | |||
Yambo generates its own input files: you just tell the code what you want to calculate by launching Yambo along with one or more '''lowercase''' options. | Yambo generates its own input files: you just tell the code what you want to calculate by launching Yambo along with one or more '''lowercase''' options. | ||
| Line 33: | Line 36: | ||
-l :GoWo Quasiparticle lifetimes | -l :GoWo Quasiparticle lifetimes | ||
-a :ACFDT Total Energy | -a :ACFDT Total Energy | ||
Any time you launch Yambo with a lowercase option, Yambo will generate the appropriate input file (default name: ''yambo.in'') and launch the <code>vi</code> editor. | |||
Editor choice can be changed at configure; alternatively you can use the <code>-Q</code> run time option to skip the automatic editing (do this if you are not familiar with <code>vi</code>!): | |||
$ yambo -x -Q | |||
yambo: input file yambo.in created | |||
$ emacs yambo.in ''or your favourite editing tool'' | |||
==Combining options== | |||
Multiple options can be used together to activate various tasks or runlevels (in some cases this is actually a necessity). | |||
For instance, to generate an input file for optical spectra including local field effects (Hartree approximation), do | |||
$ yambo -o c -k hartree ''which switches on:'' | |||
optics # [R OPT] Optics | |||
chi # [R CHI] Dyson equation for Chi. | |||
Chimod= "Hartree" # [X] IP/Hartree/ALDA/LRC/BSfxc | |||
To perform a Hartree-Fock and GW calculation using a plasmon-pole approximation, do: | |||
$ yambo -x -g n -p p ''which switches on:'' | |||
HF_and_locXC # [R XX] Hartree-Fock Self-energy and Vxc | |||
gw0 # [R GW] GoWo Quasiparticle energy levels | |||
ppa # [R Xp] Plasmon Pole Approximation | |||
em1d # [R Xd] Dynamical Inverse Dielectric Matrix | |||
Each runlevel activates its own list of variables and flags. | |||
== | ==Changing input parameters == | ||
Yambo | Yambo reads various parameters from existing database files and/or input files and uses them to suggest values or ranges. | ||
Let's illustrate this by | Let's illustrate this by generating the input file for a Hartree-Fock calculation. | ||
$ yambo -x | |||
$ yambo - | Inside the generated input file you should find: | ||
EXXRLvcs= 3187 RL # [XX] Exchange RL components | |||
% | %QPkrange # [GW] QP generalized Kpoint/Band indices | ||
1| 14| 1|100| | |||
% | % | ||
The <code>QPkrange</code> variable (follow the link for a detailed explanation) suggests a range of k-points (1 to 14) and bands (1 to 100) based on what it finds in the core database ''SAVE/ns.db1'', i.e. as defined by the DFT code. Leave that variable alone, and instead modify the previous variable to <code>EXXRLvcs= 1000 RL</code> | |||
and | |||
Save the file, and now generate the input a second time with <code>yambo -x</code>. You will see: | |||
EXXRLvcs= 1009 RL | |||
This indicates that Yambo has read the new input value (1000 G-vectors), checked the database of G-vector shells ''(SAVE/ndb.gops)'', | |||
and changed the input value to one that fits a completely closed shell. | |||
The input file generator of Yambo is thus an ''intelligent'' parser, which interacts with the user and the existing databases. For this reason we recommend that you always use Yambo to generate the input files, rather than making them yourself. | |||
== Links == | == Links == | ||
* [[Command_line_options|Command line options]] | * Next module: [[Command_line_options|Command line options]] | ||
* Back to [[First steps: a walk through from DFT to optical properties|First steps with yambo]] tutorial | |||
* [[Tutorials|Back to tutorials menu]] | * [[Tutorials|Back to tutorials menu]] | ||
Revision as of 14:58, 30 March 2017
In this tutorial you will learn how to generate and modify an input file with Yambo.
Prerequisites
Previous modules
- Initialization for bulk hBN.
You will need:
- The
SAVEdatabases for bulk hBN (Download here) - The
yamboexecutable
Input file generator
First, move to the appropriate folder and initialize the Yambo databases if you haven't already done so.
$ cd YAMBO_TUTORIALS/hBN/YAMBO $ yambo
Yambo generates its own input files: you just tell the code what you want to calculate by launching Yambo along with one or more lowercase options. (Uppercase options are considered in the following section).
To see the list of runlevels and options, run yambo -h or better,
$ yambo -H
Tool: yambo 4.1.2 rev.14024
Description: A shiny pot of fun and happiness [C.D.Hogan]
[Upper case options]
-i :Initialization
-o <opt> :Optics [opt=(c)hi is (G)-space / (b)se is (eh)-space ]
-k <opt> :Kernel [opt=hartree/alda/lrc/hf/sex]
-y <opt> :BSE solver [opt=h/d/(p/f)i]
(h)aydock/(d)iagonalization/(i)nversion
-r :Coulomb potential
-x :Hartree-Fock Self-energy and local XC
-d :Dynamical Inverse Dielectric Matrix
-b :Static Inverse Dielectric Matrix
-p <opt> :GW approximations [opt=(p)PA/(c)HOSEX]
-g <opt> :Dyson Equation solver
[opt=(n)ewton/(s)ecant/(g)reen]
-l :GoWo Quasiparticle lifetimes
-a :ACFDT Total Energy
Any time you launch Yambo with a lowercase option, Yambo will generate the appropriate input file (default name: yambo.in) and launch the vi editor.
Editor choice can be changed at configure; alternatively you can use the -Q run time option to skip the automatic editing (do this if you are not familiar with vi!):
$ yambo -x -Q yambo: input file yambo.in created $ emacs yambo.in or your favourite editing tool
Combining options
Multiple options can be used together to activate various tasks or runlevels (in some cases this is actually a necessity). For instance, to generate an input file for optical spectra including local field effects (Hartree approximation), do
$ yambo -o c -k hartree which switches on: optics # [R OPT] Optics chi # [R CHI] Dyson equation for Chi. Chimod= "Hartree" # [X] IP/Hartree/ALDA/LRC/BSfxc
To perform a Hartree-Fock and GW calculation using a plasmon-pole approximation, do:
$ yambo -x -g n -p p which switches on: HF_and_locXC # [R XX] Hartree-Fock Self-energy and Vxc gw0 # [R GW] GoWo Quasiparticle energy levels ppa # [R Xp] Plasmon Pole Approximation em1d # [R Xd] Dynamical Inverse Dielectric Matrix
Each runlevel activates its own list of variables and flags.
Changing input parameters
Yambo reads various parameters from existing database files and/or input files and uses them to suggest values or ranges. Let's illustrate this by generating the input file for a Hartree-Fock calculation.
$ yambo -x
Inside the generated input file you should find:
EXXRLvcs= 3187 RL # [XX] Exchange RL components %QPkrange # [GW] QP generalized Kpoint/Band indices 1| 14| 1|100| %
The QPkrange variable (follow the link for a detailed explanation) suggests a range of k-points (1 to 14) and bands (1 to 100) based on what it finds in the core database SAVE/ns.db1, i.e. as defined by the DFT code. Leave that variable alone, and instead modify the previous variable to EXXRLvcs= 1000 RL
Save the file, and now generate the input a second time with yambo -x. You will see:
EXXRLvcs= 1009 RL
This indicates that Yambo has read the new input value (1000 G-vectors), checked the database of G-vector shells (SAVE/ndb.gops), and changed the input value to one that fits a completely closed shell.
The input file generator of Yambo is thus an intelligent parser, which interacts with the user and the existing databases. For this reason we recommend that you always use Yambo to generate the input files, rather than making them yourself.
Links
- Next module: Command line options
- Back to First steps with yambo tutorial
- Back to tutorials menu