Short Range Order Effect in X-Ray Diffuse Scattering Due to Orientational Disorder

X-ray diffuse scattering due to orientational disorder is discussed in the disordered phase of a crystal having molecules with multiple orientations. The Bethe approximation is extended to multi-orientational system so that the short range correlation can be incorporated in the correlation function. The intensity of the diffuse scattering is written in terms of the probabilities of the pair configurations of the neighboring molecules.