Temperature and Pressure Effect on the Raman Frequencies Calculated from the Crystal Volume in the gamma-Phase of Solid Nitrogen

The temperature and pressure dependences of the Raman frequencies of the lattice modes (E-g and B-1g modes) and of an internal mode (2331 cm(-1)) are predicted using the observed molar volume data from the literature in the gamma-phase of solid N-2. This calculation is carried out by means of the mode Gruneisen parameter of each Raman mode in the gamma-phase of solid nitrogen. Our results show that the predicted Raman frequencies of the E-g mode increase as the pressure increases. The Raman frequencies of the other lattice mode (B-1g) and the internal mode (2331 cm(-1)) decrease with increasing pressure due to their negative Gruneisen parameters in the gamma-phase of solid N-2. The temperature effect on the Raman frequencies is negligibly small