Accession Number:

AD0688476

Title:

MICROSCOPIC THEORY OF FORCE CONSTANTS IN SOLIDS,

Descriptive Note:

Corporate Author:

CHICAGO UNIV ILL JAMES FRANCK INST

Report Date:

1969-01-01

Pagination or Media Count:

35.0

Abstract:

The expression of the force constants are derived from the energy of a neutral system of interacting nuclei and electrons. Those force constants depend only on the nuclear charges and the inverse dielectric function of the electronic system. It is verified that they fulfill the general symmetry, translational and rotational invariance properties required by the Born-Van Karman theory. When the role of the core electrons is neglected, those force constants can be evaluated in metals from the bare ionic potentials. In insulators, the existence of long wave length acoustical phonons implies that the inverse dielectric function satisfies a certain number of sum rules. The method becomes more difficult to apply, which explains the general use of phenomenological models. Author

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE