The temperature factor of an atom in a rigid vibrating molecule. II. Anisotropic thermal motion

The analysis in part I is generalized to any crystal containing rigid molecules which undergo anisotropic translational and librational motion about a site fixed by symmetry. The treatment is correct to terms in (u_i²)² and (ω_i²)², where (u_i²) is the mean-square translational displacement of the molecule along the ith axis and (ω_i²) is the mean-square angular libration about the same axis. The first-order treatment to terms in (u_i²) and (ω_i²) is shown to be equivalent to the rigid-body theory in current use.