Solutions solides pour la détermination des constantes de force dans les solides

Abstract

The force constants in solids are usually greater in number than the fundamental frequencies. Spectroscopic study of solid solutions—isotopic molecules at low concentrations (crystalline solid solutions) or frozen solutions (non crystalline solid solutions at liquid nitrogen temperature)—allow to obtain supplementary data which facilitate the resolution of the secular equations. The intramolecular constants in the solid are thus obtained. In the examples studied, it is possible to deduce from these data the intermolecular constants between congruent molecules.