On the distribution of local quadrupolarisations in the orientational glass H2

Abstract
Presents a detailed study of the NMR spectra of solid H2 in the intermediate ortho-concentration regime (0.20<or=X<or=0.55). This system displays a glassy orientational behaviour resulting from quadrupolar interactions and site disorder. The authors obtain the distribution functions for the local quadrupolarisations which describe the extent to which the molecular orientations are frozen. They observe broad distributions that evolve only smoothly with temperature. This behaviour suggests a continuous growth of quadrupolarisation on cooling without any abrupt transition.