Second order Raman spectrum of carbon disulphide in the condensed phase

Abstract

AbstractBelow 162K, carbon disulphide crystallizes in the space group D2h18 with two molecules in the primitive cell. The internal modes v1, v2 and v3 of the isolated CS2 molecule are split due to static and correlation field splittings. Anderson et al. have extensively studied the Raman and infrared spectra of CS2 at 79 K and 18 K and have analysed the internal and external modes with a lattice dynamical calculation of the q = 0 phonons. However, their spectra reveal the presence of extensive second order features accompanying the v1, v2, v3 and 2v1 bands. The present investigation attempts an interpretation of these second order Raman spectra employing Born's theory and the lattice dynamical calculation of phonons at all allowed q points in the Brillouin zone employing the rigid molecule approximation.