Raman Spectrum of Carbon Disulphide

The Raman spectrum of liquid carbon disulphide has been investigated with high dispersion. In addition to the lines already known, five very faint lines have been observed. The intensities of the stronger lines were measured and, with a spectrograph of low dispersion, the degrees of depolarization of the two principal bands were determined. The results are in accord with the assumption made by Fermi, Dennison and Placzek that large perturbations of some of the energy levels occur on account of the approximate coincidence of v(1) with 2(v2). The values Delta = -120 cm(-1) and vertical bar P vertical bar = 17.8 cm(-1) are obtained for the difference Delta = v(1) - 2(v2) and for the coupling constant P = beta h(1/2)/4 pi(2)mu(1/2)(1)mu(2)(v(1) + 2(v2))(1/2).