Vibrational spectra and lattice dynamics of the ?-phase of white phosphorus

We report on a study of the alpha-and beta-phases of white phosphorus using infrared and Raman spectroscopy. The spectra of the beta-phase were measured at a temperature of 10 K with a sufficiently high resolution - allowing, for the first time, observation of the crystalline splitting of the bands corresponding to molecular vibrations. The band corresponding to the v1 (A1) vibration splits into six components. The bands corresponding to the v3 (F2) and the v2 (E) vibrations split into 17 and 12 components, respectively. The half-width (FWHM) of the bands in the infrared spectra range within 0.2-0.3 cm-1, and FWHM for the bands in Raman spectra is about 0.15 cm-1. Based on ab initio calculations, symmetry analysis and our vibrational spectra, conclusions are drawn about the lattice dynamics of the beta-phase of white phosphorus.