THE INFLUENCE OF ANISOTROPIC THERMAL VIBRATIONS ON ABSORPTIVE FORM-FACTORS FOR HIGH-ENERGY ELECTRON-DIFFRACTION

Thermal diffuse scattering is the dominant contribution to the absorpt ive form factors in high-energy electron diffraction. So far, calculat ions have been limited to isotropic thermal vibrations. In this paper, a general formula is given for the absorptive form factors that fully accounts for anisotropic temperature factors. The resulting formula i s based on the Einstein model and well suited for numerical evaluation . A case study shows that even slight deviations from isotropy lead to a strong directional dependence of the absorptive form factors.