Direct Observation of IsolatedJ=1Pairs in Solid Deuterium and Hydrogen by Raman Scattering

Abstract

Spectra due to the orientational states of isolated $J=1\mathrm{}$ impurity pairs in solid hydrogen and deuterium have been observed by Raman scattering in the wave-number range 2.3-7 ${\mathrm{cm}}^{-1\mathrm{}}$. The results give a direct measure of the pair energy levels and can be used to determine the anisotropic pair interactions. To within experimental accuracy, no deviation from the dominant electric quadrupole-quadrupole interaction was observed. Expressions are developed for the scattering efficiency which agree well with experiment. Zero-point-motion averages of the interactions are calculated using several quantum crystal wave functions and a comparison is made with the measured frequencies. The collective wave functions give better agreement with experiment than the Hartree single-particle wave functions.