Orientational glass
In solid-state physics, an orientational glass is a molecular solid in which crystalline order and [disorder (physics)|long-range order] coexists with quenched disorder in some Degrees of [freedom (mechanics)|rotational degree of freedom].
An orientational glass is either obtained by quenching a plastic crystal,, or it is a mixed crystal in which positional disorder causes additional disorder of molecular orientations, e.g. CN orientations in KCN:KBr.