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how to plot phonon dispersion curve
Posted: Wed Aug 16, 2023 12:53 am
by benali_djebour
Dear VASP users,
after a DFPT calculation (using VASP.6.4.2), how to plot dispersion curve (based on OUTCAR or vasprun.xml) ? or should we use phononpy ?
Thank you in advance
Re: how to plot phonon dispersion curve
Posted: Wed Aug 16, 2023 8:06 am
by manuel_engel1
VASP supports the calculation of phonon frequencies and eigenvectors via the
LPHON_DISPERSION INCAR tag. Since VASP 6.4.2, this properly includes DFPT calculations. You must supply the q-points at which to calculate the phonons in the
QPOINTS file. These q-points are given with respect to the primitive cell determined by VASP (see symmetry section in OUTCAR).
We recommend parsing the calculated phonon spectrum from the vaspout.h5 file ("/results/phonons/").
Alternatively, the phonon frequencies are also found in the OUTCAR file ("Phonons" section).
You can control the amount of OUTCAR output with the
PHON_NWRITE tag.
If your material is polar, you can set
LPHON_POLAR to account for electrostatic interactions (LO-TO splitting). For this, you need to also specify the
Born effective charges and the
static dielectric tensor.