Ca(OH)2 and Ca(OD)2 Vibrational Crystal Spectra, Normal Coordinate Analysis, and Assignment

Abstract

In this paper further experimental studies of the vibrational spectra of Ca(OH)₂ and its deutero‐modification are reported. Furthermore, a normal coordinate analysis of the crystal spectrum in harmonic approximation is given, based on a method for construction of symmetry coordinates and factorization of the eigenvalue problem given in a preceding paper. Numerical calculation of a considerable part of the dispersion surface is included, using force constants derived from a lattice model with Coulomb and repulsive forces. An assignment of the infrared spectrum is given. In particular the OH‐stretching region is discussed in terms of transitions between critical points of the dispersion surface.