The disordered solid phases of potassium cyanide

Abstract

Molecular dynamics calculations have been carried out for the orientationally disordered phases of solid potassium cyanide. It has been found that the properties of the simulated crystal are very sensitive to the assumed charge distribution of the cyanide ion and that there is a strong correlation between the static and dynamic consequences of assumptions about the form of the interionic potential. Results are reported for the orientational distribution of the cyanide ions and for time correlation functions relevant to polarised Raman and inelastic neutron scattering experiments. The anomalous dispersion characteristic of transverse acoustic phonons in phase I is shown to be reproducible, but no single model has been found that will account for all the existing experimental data.