Molecular properties of CN− ions in alkali cyanide crystals

Abstract

A b initio coupled Hartree–Fock calculations of the multipole moments and dipole polarizability of CN− in the high temperature solid phase of NaCN are reported and compared with results for the free anion. The size, polarizability, and anisotropy of the electron cloud are all considerably reduced in the crystal. The variation of these properties with the orientation of CN− in the cation cage is also investigated and found to be small. These findings give a microscopic basis for models derived from molecular dynamics simulations of alkali cyanide crystals.