Polymorphic transitions in highly compressed molecular nitrogen. Application of Mayer group expansion for solids

摘要

We applied the Mayer group expansion method for solids to predict locations of the polymorphic phase transitions lines between molecular e and zeta phases, as well as between molecular zeta phase and polymeric cubic-gauche-phase in highly compressed nitrogen solid. A simple potential model is proposed and its parameters are determined using known ab initio energy calculations for the molecular alpha phase. The results are compared with existing experimental data and the influence of intermolecular correlations on the temperature dependence of phase transition pressures is estimated.