Electron-phonon interactions from Monte-Carlo sampling

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Revision as of 10:07, 9 April 2019 by Karsai (talk | contribs)

Important: This feature will be only available from VASP6.0 or higher.

First of all this method needs a sufficiently large super cell. It also involves phonon calculations for the [math]\displaystyle{ \Gamma }[/math] point (see Phonons from finite differences). So many tags in the INCAR will be used from the phonon calculations.

To enable electron-phonon interactions from MC methods PHON_LMC=.TRUE. has to be set in the INCAR file. Also IBRION=6 has to be selected (the MC method is currently only implemented for IBRION=6).

Full MC sampling

The tag PHON_NSTRUCT sets the number of structures generated due to the MC sampling. Convergence of the observable with respect to this number should be monitored.

The tag TEBEG=0 is also needed to choose the temperature at which the sampling is run.

Additionally the PHON_LBOSE can be set .TRUE. or .FALSE. (default PHON_LBOSE=.TRUE.), which selects Bose-Einstein or Maxwell-Boltzmann statistics, respectively.

A sample INCAR file for 0 K looks like the following:

System = DEFAULT
PREC = Accurate
ISMEAR = 0; SIGMA = 0.1;
IBRION = 6

PHON_LMC = .TRUE.
PHON_NSTRUCT = 100
TEBEG = 0.0


== ZG configuration (one-shot sampling)


A sample INCAR file for the