Abstract
The lattice dynamics of beryllium, a metal with hexagonal close-packed structure and two atoms per unit cell, is investigated within the framework of Harrison's first-principles pseudopotential theory, using (i) the Slater approximation for the conduction-band-core exchange, and (ii) a modified dielectric-screening function employing the Kohn-Sham approximation for exchange among the conduction electrons. The energy-wave-number characteristic is constructed from the Hartree-Fock-Slater (HFS) wave function for ; this is used to calculate the phonon dispersion relations in the [0001], [], and [] directions. Good agreement is obtained with neutron diffraction experiments. The three independent elastic shear constants are also calculated from ; good agreement with experiment is obtained for and , but only fair results obtain for .
- Received 15 April 1970
DOI:https://doi.org/10.1103/PhysRevB.2.1733
©1970 American Physical Society