Molecular vibrational spectroscopy by inelastic x-ray scattering: Experimental determination of the absolute vibrational cross section in liquid nitrogen - art. no. 212102

Inelastic x-ray scattering (IXS) is used to measure the vibrational spectru m of liquid nitrogen at a temperature of 76 K and a pressure of 1 bar as a function of wave vector q in the 1.45-11.8 A(-1) range. The absolute IXS cr oss section for the vibrational excitation is determined in the explored q range. Its comparison with a theoretical calculation is very satisfactory, and leads to a precise determination of the intramolecular distance and the vibrational root-mean-square displacement. This demonstrates that the IXS technique can provide accurate information on the vibrational dynamics in m olecular systems. The peculiarities of IXS with respect to other vibrationa l spectroscopies are briefly discussed.