phono3py/example/Si-PBEsol

This is the example of silicon calculation. The supercell is 2x2x2 of the conventinal unit cell. The VASP calculation was made for force calculations with 300 eV, 2x2x2 off-Gamma-centre k-point sampling mesh for the supercell, and PBE-sol. Silicon crystal is F-centre, so there is the transformation matrix from the conventinal unit cell to the primitive cell.

phono3py_disp.yaml is generated by

% phono3py -d --dim="2 2 2" -c POSCAR-unitcell --pa="F"

To create fc3.hdf5 and fc2.hdf5,

% phono3py --sym-fc

Using 11x11x11 sampling mesh, lattice thermal conductivity is calculated by

% phono3py --mesh="11 11 11" --fc3 --fc2 --br

kappa-m111111.hdf5 is written as the result. The lattice thermal conductivity is calculated as 109.0 W/m-K at 300 K. This becomes, with 19x19x19 sampling mesh, 123.2 W/m-K.

Accumulated lattice thermal conductivity is calculated using 'phono3py-kaccum' script.

% phono3py-kaccum --pa="F" -c POSCAR-unitcell kappa-m111111.hdf5 |tee kaccum.dat

The plot of this result is shown in Si-kaccum.png. It is found that most of the lattice thermal conductivity owes the phonon modes below 6 THz.

fc2.hdf5 can be read by harmonic phonopy to rename it to force_constants.hdf5. The phonon band structure and DOS are watched by

% ln -s fc2.hdf5 force_constants.hdf5
% phonopy --dim="2 2 2" --pa="F" -c POSCAR-unitcell --mesh="19 19 19" --band="1/2 1/2 0 0 0 0 1/2 1/2 1/2" --hdf5 --readfc -p

Si-band-DOS.png shows this plot. The shape of phonon DOS below 6 THz is similar to the derivative of the accumulated lattice thermal conductivity, i.e., the heat is conductied by the low frequency longitudinal-acoustic-like modes.


The file 'vasprun_xmls.tar.lzma' in this example contains vasprun.xml's that are used to generate FORCES_FC3. To test the FORCES_FC3 generation, after decompressing this file, the following command is executed at current directory:

% phono3py --cf3 vasprun_xmls/disp-{00001..00111}/vasprun.xml