Showing papers by "David Vanderbilt published in 1991"
TL;DR: Test d'un cadre pour the construction des pseudopotentiels separables ultra-mous proposes recemment par Vanderbilt dans le contexte des calculs de dynamique moleculaire «ab initio» de Car-Parrinello sur les atomes et les molecules.
Abstract: A scheme for the construction of ultrasoft separable pseudopotentials recently proposed by Vanderbilt is tested in the context of Car-Parrinello ab initio molecular-dynamics calculations on atoms and molecules. For the case of oxygen, the transferability of the pseudopotential is demonstrated by comparing the calculated properties of molecular ${\mathrm{O}}_{2}$ and ${\mathrm{O}}_{3}$ with those obtained from conventional approaches. Converged results are obtained using plane-wave-basis cutoffs of only \ensuremath{\sim}25 Ry. Forces can be calculated efficiently, and a molecular-dynamics simulation of molecular vibration is demonstrated.
383 citations
TL;DR: In this article, a realistic ab initio calculation of the contribution of cubic anharmonicity to the inverse lifetime and frequency shift of phonons in silicon was carried out, where the cubic coupling constants for phonons throughout the Brillouin zone were obtained from an anharmonic Keating-type lattice-dynamical model.
Abstract: We have carried out a realistic ab initio calculation of the contribution of cubic anharmonicity to the inverse lifetime \ensuremath{\Gamma} and the frequency shift \ensuremath{\Delta} of phonons in silicon. The cubic coupling constants for phonons throughout the Brillouin zone are obtained from an anharmonic Keating-type lattice-dynamical model, which has been fit to a database of results from local-density-approximation frozen-phonon and elastic-modulus calculations. \ensuremath{\Gamma} and \ensuremath{\Delta} have been calculated as a function of temperature T and wave vector. Our results agree reasonably well with experiment, but indicate the need for retention for quartic and higher-order terms, especially at high T.
50 citations