Intermolecular interactions in the epsilon phase of solid oxygen studied by infrared spectroscopy.

The infrared spectra of solid oxygen, in the overtone region, have been measured in the ? and in the ? phases at low and room temperature up to 60 GPa. The two structured bands observed in the ? phase are assigned to the combination of the infrared active mode with itself and with the Raman active mode, respectively. Performing a deconvolution of the spectral profile the densities of states of the infrared and Raman active vibrational modes are obtained.