| Numéro |
J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981
International Conference on Phonon Physics
|
|
|---|---|---|
| Page(s) | C6-649 - C6-651 | |
| DOI | https://doi.org/10.1051/jphyscol:19816189 | |
International Conference on Phonon Physics
J. Phys. Colloques 42 (1981) C6-649-C6-651
DOI: 10.1051/jphyscol:19816189
1 CNRS and Université P. et M. Curie, Tour 13-22, 4 pl. Jussieu, 75230 Paris cedex 05, France
2 Xerox Research Center, 3333 Coyote Hill Road, Palo Alto, California 94304, U.S.A.
J. Phys. Colloques 42 (1981) C6-649-C6-651
DOI: 10.1051/jphyscol:19816189
AB INITIO FORCE CONSTANTS OF GERMANIUM
K. Kunc1, 2 et R.M. Martin1, 21 CNRS and Université P. et M. Curie, Tour 13-22, 4 pl. Jussieu, 75230 Paris cedex 05, France
2 Xerox Research Center, 3333 Coyote Hill Road, Palo Alto, California 94304, U.S.A.
Abstract
Using the local density-functional formalism, phonon frequencies can be predicted ab initio by comparing the energy of the equilibrium configuration with the one having the atoms displaced in a pattern corresponding to a "frozen" phonon. Here we show that by using less symmetric displacement patterns and by applying the Hellman-Feynman theorem to the self-consistent electronic charge densities, one can obtain al1 force constants determining the entire branches of phonon spectra corresponding to a selected direction of propagation. Our method is illustrated on the example of r-x branches of phonon spectra in Ge.