Ya. Freiman et al., BROKEN SYMMETRY PHASE-TRANSITION IN SOLID HD - QUANTUM BEHAVIOR AT VERY HIGH-PRESSURES, Journal of low temperature physics, 113(5-6), 1998, pp. 723-728
The broken symmetry phase.(BSP) transition in solid HD has been shown
to be an example of quantum orientational melting. Anomalous features
observed for the transition are a consequence of the symmetry properti
es of the system, namely, the fact that in HD all rotational states an
d transitions between them are allowed in contrast to the behavior of
the homonuclear H-2 and D-2.