Molecular Dynamics of the Phase Transition in Deuteroammonium Chloride

Abstract

Computer simulation studies have been made to investigate the phase transition in ND 4CI at low temperature. Two different types of potential have been used to represent the interaction between ND t and CI-: (i) the Lennard Jones potential and (ii). the twelfth inverse power or r -12 repulsive potential. The present study reveals the occurrence of a phase transition in N-D 4CI in a well-defined region. The Lennard Jones potential appears to be more appropriate in depicting the two welldefined phases known as II and III in the literature. The energy pattern curves obtained in this study give us the nature of the rotational behaviour of ND:' before and after the transition at 249 K.The libration frequency of the ND t ion is estimated to be of the order of 130 em -1.