Calculation of the spectral transition frequencies of matrix-isolated H2, D2, and HD impurities in solid Kr and Xe under pressure

The vibrational, rotational, and vibrational-rotational spectra of dilute H2, D2, and HD molecules matrix-isolated in solid Kr and Xe are calculated at zero temperature and at pressures 0 ≤ P ≤ 570 kbar. The impurity local mode frequencies are also calculated vs. pressure. It is found that the pure vibrational and rotational-vibrational transition frequencies are strongly red shifted in the solid at P = 0 with respect to their gas-phase values, and the pure rotational transitions are weakly red shifted. The agreement with Raman and infrared results is generally but not uniformly good. As the pressure is increased, the transition frequencies of all the modes in solid Xe and some in solid Kr red shift with respect to their values in the solid at P = 0. But at higher pressures all modes are strongly blue shifted. The local mode frequencies strongly blue shift for all P > 0