Spectroscopic modification of the Pippard relation applied for the translational mode in ammonia solid II near the melting point

This study gives our calculation for the frequency shifts 1v∂v∂TP and the specific heat CP near the melting point in the ammonia solid II. We establish a linear relationship between CP and 1v∂v∂TP using the Raman frequencies of the translational mode which we calculated in this system. This leads to the validity of the spectroscopic modification of the first Pippard relation in the ammonia solid II near the melting point. From this linear variation of CP with the 1v∂v∂TP we deduce the slope values of dPmdT near the melting point for the fixed pressures of 3.65, 5.02 and 6.57 kbar in the ammonia solid II. They are compared with the experimental dPmdT values for this system.