Lattice dynamics of rubidium

Abstract

A study of the lattice vibrations in rubidium at different temperatures is undertaken by employing a pseudopotential form factor. This potential is derived from a scaling procedure developed in a totally different context. Excellent agreement with experiments was obtained at low temperatures. At higher temperatures, the found deviations are due to anharmonic shifts. The calculated Debye temperatures agree with the experimentally assigned values. The present calculation predicts correctly the bcc phase to be the stable atomic configuration. However, this result is only obtained when the zero point vibrational energy is included in the energy expression.