Lattice Dynamics and Anharmonic Effects in AgCl

Abstract

Abstract The lattice vibrations of AgCl are calculated from an extended shell model where the shell of the Ag‐ion has a quadrupolar and a rotational degree of freedom. The model parameters are discussed in connection with the electronic 4d‐shell of the Ag‐ion. Thermal expansion, infrared reflection, and anharmonic frequency shift are calculated from a simple extension of the harmonic model, and are found to be in good agreement with experimental data. The anharmonic effects are comparable to those of the alkali halides.