THE RAMAN SPECTRA OF LIQUID AND SOLID H₂, D₂, AND HD AT HIGH RESOLUTION

Abstract

The Raman spectra of liquid (~18° K) and solid (~2° K) n-H 2 , p-H 2 , n-D 2 , o-D 2 (80%), and HD were photographed with a reciprocal linear dispersion of 3 to 6 cm −1 per mm. The S 0 rotational lines show broadening of a few cm −1 but the Q 1 vibrational lines are very sharp. The S 0 (0) transition of p-H 2 and o-D 2 is a triplet of sharp lines, but the corresponding transition in HD is not split. The vibrational frequencies in the liquid are lowered by 7 to 9 cm −1 and in the solid by 8 to 11 cm −1 from the gas values. The Raman spectrum of p-H 2 has been discussed in detail by Van Kranendonk. In the present communication the vibrational shifts in the various solids are correlated by representing them as the sums of shifts due to dispersion forces, overlap forces, and vibrational coupling.