Accession Number : AD0601879

Title :   A CALCULATION OF THE PHONON FREQUENCIES IN SODIUM.

Descriptive Note : Technical rept. no. 18

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA

Personal Author(s) : Sham,L. J.

Report Date : 09 APR 1964

Pagination or Media Count : 32

Abstract : The phonon spectrum of sodium is calculated in the harmonic approximation. The effective interaction between the ions is separated into direct two-body forces between bare ions and effective attraction due to the presence of conduction electrons. Careful treatment of the two phonon processes includes the calculation of the electron-phonon scattering based on the pseudo-potential method and the screening effects due to the interaction between electrons by the Hartree-Fock approximation with a screened exchange potential. Comparison of the results for sodium with neutron diffraction measurements and a previous calculation by Toya shows good agreement on the whole. (Author)

Descriptors :   (*SODIUM, PHONONS), (*PHONONS, FREQUENCY), CRYSTAL LATTICES, ACOUSTIC PROPERTIES, QUANTUM THEORY, IONS, ELECTRONS, POTENTIAL SCATTERING, NEUTRON DIFFRACTION, ATOMIC ENERGY LEVELS, NUMERICAL ANALYSIS, HARMONIC ANALYSIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE