THE EFFECT OF PRESSURE ON THE MOLECULAR-STRUCTURE OF HG(CN)2 AND THE ANOMALOUS PRESSURE-DEPENDENCE OF THE PHONON FREQUENCIES

Anomalous pressure-induced phonon frequency shifts of certain lattice modes and of the v7 internal bending mode and the nonlinear pressure dependence of the phonon frequencies have been observed in the pressure range 0-16.5 kbar for the Raman spectrum of crystalline Hg(CN)2. The mechanism of these pressure effects is discussed in terms of the strong intermolecular interaction and the molecular configurational distortion in the crystal. The effect of pressure on the molecular structure of Hg(CN)2 is discussed in relation to the pressure dependence of the internal stretching frequencies. © 1980 American Institute of Physics.