On the vibrational properties of CsD₂PO₄ crystal

Abstract

Lattice dynamics simulation of CsD 2 PO 4 crystal is performed in a quasiharmonic approximation using the atomistic potential involving Coulomb, short-range, covalent, van der Waals and hydrogen-bonded interactions. The phonon dispersion relations, partial density of states, velocities of ultrasonic waves and atomic displacement parameters are calculated both in the paraelectric and ferroelectric phases. The obtained data enable us to give a detailed description of the observed Raman and IR spectra and to determine the eventual local symmetry of the PO 4 groups.