Far infrared absorption spectra in liquid and solid H2

Abstract

The far infrared absorption spectra of hydrogen have been measured in solid and liquid phases in the frequency range 300–800 cm−1. We have found a remarkable similarity between the liquid and solid spectra. In the solid phase, we have performed measurements at different ortho-H2 concentrations, in order to investigate the influence of ortho-H2 molecules. In particular, we have studied the behaviour of the S(0) line at low ortho-H2 concentrations. We found that the rotational exciton picture describes our results well.