Ab initio description of large amplitude motions in solid N2. I. Librons in the ordered alpha and gamma phases

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