A b i n i t i o description of large amplitude motions in solid N2. I. Librons in the ordered α and γ phases

Abstract

Starting from an a b i n i t i ointermolecular potential, we have calculated the mean field states for the librations in the ordered α and γ phases of solid N2, using a basis of spherical harmonics up to l max=12. The correlation between the mean field solutions was then taken into account via a libron model based on the random‐phase approximation or time‐dependent Hartree method. The calculated librational frequencies are rather accurate, showing that the discrepancies in earlier results with the a b i n i t i o potential are mainly due to the breakdown of (quasi‐)harmonic models for the librations, even in the ordered phases.