Effect of thermal vibrations on the scattering of X-rays. Ill

The first section of this paper contains a comparison of Sir C. V. Raman’s explanation of the diffuse scattering with the so-called ‘thermal’ theory. It is shown that Raman’s demand of a theory based on quantum principles is satisfied by the modern forms of the thermal theory. The second part of the paper deals with the relation of the dynamical matrix (describing the mechanical properties of the lattice) and the scattering matrix (describing the scattering power). In the last section the influence of the ordinary Raman effect (mutual deformation of atoms) on the scattering is derived.