phonopy/example/Al2O3

Corundum Al2O3

Forces were calculated in the 2x2x1 supercell of the hexagonal lattice by VASP with 500eV cutoff energy and 6x6x1 k-point mesh. Dielectric constant and Born effective charge tensors were calculated with the hexagonal unit cell. The Wyckoff positions are c and e, respectively, which can be found by

% phonopy -c POSCAR-unitcell --symmetry --pa=auto

phonopy_disp.yaml is created by

% phonopy -d --dim 2 2 1 --pa auto -c POSCAR-unitcell

The band structure is plotted using seekpath by

% phonopy-load --band auto -p

where seekpath can be installed by pip install seekpath.