# Phonon bands with LO-TO from PHBST.nc¶

This example shows how to plot the phonon band structure of AlAs including the LO-TO splitting. These resultas tutorial/lesson_rf2.html

Open PHBST file produced by anaddb and extract the phonon bands object. (alternatively one can use the shell and abiopen.py OUT_PHBST.nc -nb to open the file in a jupyter notebook.

from abipy.abilab import abiopen
import abipy.data as abidata

with abiopen(abidata.ref_file("ZnSe_hex_886.out_PHBST.nc")) as ncfile:
phbands = ncfile.phbands


Phonon frequencies with non analytical contributions, if calculated, are saved in the anaddb.nc file produced by anaddb. The results should be fetched from there and added to the phonon bands. Notice that all the directions starting from or arriving at gamma that are used in the path should explicitely calculated, even if the values are the same.

phbands.read_non_anal_from_file(abidata.ref_file("ZnSe_hex_886.anaddb.nc"))


Plot the phonon frequencies. Note that the labels for the q-points are found automatically by searching in an internal database.

phbands.plot(title="ZnSe with LO-TO splitting")


Out:

<Figure size 640x480 with 1 Axes>


For the plotly version, use:

phbands.plotly(title="ZnSe with LO-TO splitting")


Total running time of the script: ( 0 minutes 0.661 seconds)

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