PHONON Software
PHONON, Version 2.11
Last update: January 25, 2000
Phonon is a software for calculating phonon
dispersion curves, and phonon density spectra
of crystals from either a set
of force constants, or from a set of
Hellmann-Feynman forces calculated within an ab initio
(external) program.
Phonon builds a crystal structure, using one of the 230
crystallographic space groups,
finds the neighbor list and the symmetry of force constant
matrices.
It builds the dynamical matrix, diagonalizes it,
and calculates the phonon dispersion relations
along any line of the reciprocal space.
Phonon
finds the polarization vectors, and the irreducible representations
of the phonon modes at Brillouin zone center,
and calculates the total and partial phonon density of states.
Such calculations are done for neighbor list with
any coordination shells, or within any supercell
with periodic boundary conditions.
For polar cystals
the LO/TO mode splitting can be included.
In unstable structures Phonon finds soft modes.
Therefore, it can be used to search for the stability of
structures, and for phase transitions.
The program allows to calculate phonons
for model with atoms of reduced number
of degree of freedom, and/or for models consisting of rigid molecules.
Within the supercell approach
it permittes to calculate the ab initio phonons
for bulk crystals, surfaces, films, crystal with
vacancies, substitutional and interstitial impuritues,
etc.
See: