phonon dispersion spectra (DFPT method) VASP 5.3.3 + phonopy 1.10

1. Installation of phonopy

　　ubuntu12.04 + python3.5.0

　　(1) some pack

　　　　　　

sudo apt-get install python2.7-dev python-numpy python-matplotlib python-tk python-lxml python-yam

 

　　　　　maybe some of them are useless, uhmmmmmm.....even I don't know what they mean.

　　(2) phonopy 

　　　　　　

sudo python setup.py install

 

2. VASP & phonopy, DFPT method

　　(1) relax the coordinate with a high accuracy by VASP. We will use the POSCAR, maybe the CONTCAR.

　　(2) copy and rename the coordinate file to POSCAR-unitcell

　　(3) some command

　　　　　　

phonopy -d --dim="2 2 2" -c POSCAR-unitcell

mv SPOSCAR POSCAR

 

　　(4) now we will calculate force constants of the supercell by VASP

　　　　IMPORTANT: IBRION = 8, NSW = 1, LREAL = .FALSE

　　　　NOTICE:    NO NPAR!

　　　　the INCAR may be such like

　　　　　　　　　　

PREC = Accurate
ENCUT = 500

IBRION = 8
EDIFF = 1.0e-08
IALGO = 38
ISMEAR = 0; SIGMA = 0.1
LREAL = .FALSE.
ADDGRID = .TRUE.
LWAVE = .FALSE.
LCHARG = .FALSE.

 

　　(5)after a longtime caculation, we will find the vasprun.xml.

　　　　　　　　

phonopy --fc vasprun.xml

 

　　　　we get the FORCE-CONSTANT

　　　　then, we should make a file named xxx.conf(maybe band.conf), which contains some parameters.

　　　　　　　　it may like this

ATOM_NAME = Na Cl
DIM = 2 2 2
PRIMITIVE_AXIS = 0.0 0.5 0.5  0.5 0.0 0.5  0.5 0.5 0.0
BAND = 0.0 0.0 0.0  0.5 0.0 0.0  0.5 0.5 0.0  0.0 0.0 0.0  0.5 0.5 0.5
FORCE_CONSTANTS = READ

 

　　　　then, we use this command

　　　　　　　　

phonopy --dim="3 3 3" --readfc  -c ../unitcell band.conf

 

　　　　we get the band.yaml, then

phonopy-bandplot --gnuplot band.yaml > phono.dat

 

　　(6)finally, put the phono.dat into origin, matlab, MS excel and etc. 

 

Reference: phonon manual.