We propose a theoretical description of a possible orientational glass transition in solid molecular para-hydrogen and ortho-deuterium under pressure supposing that they are mixtures of $J=0$ and $J=2$ states of molecules. The theory uses the basic concepts and methods of standard spin-glass theory. We expect our orientational glass to correspond to the ${\mathrm{II}}^{\prime }$ phase of the high-pressure hydrogen phase diagram.

• Received 4 September 2008

DOI:https://doi.org/10.1103/PhysRevE.79.021105