A model for the determination of the crystal field potential in H 2 and D 2 from high pressure experiments

Abstract

We present a model which permits an experimental test of the crystal-field function B( R), in solid hydrogen at high density. We show that B( R) is dominantly responsible for the roton-phonon coupling. The coupling parameter, determined from level anticrossing phenomena, yields a value of d B( R)/d R − 2 B( R)/ R, substantially smaller than predicted from ab initio pair potentials. Sources of this discrepancy are discussed.