Accession Number : AD0688476

Title :   MICROSCOPIC THEORY OF FORCE CONSTANTS IN SOLIDS,

Corporate Author : CHICAGO UNIV ILL JAMES FRANCK INST

Personal Author(s) : Cohen,Morrel H. ; Martin,Richard M. ; Pick,Robert M.

Report Date : 1969

Pagination or Media Count : 35

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)

Descriptors :   (*MOLECULAR ASSOCIATION, SOLIDS), BAND THEORY OF SOLIDS, CHEMICAL BONDS, WAVE FUNCTIONS, PHONONS

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE