Vibration amplitudes of atoms in cubic crystals

Root-mean square amplitudes of atomic vibration are given for twenty elements and twenty-four compounds crystallizing in the cubic system. The spatial distribution of atomic displacements due to thermal vibration is calculated from the elastic constants of nineteen cubic crystals, and attention is drawn to the relationships existing between the amplitudes of pure longitudinal and transverse waves travelling along the cube edges, face diagonals and cube diagonals, and the structures of these crystals. From the data given, the intensity of diffuse scattering power could be plotted in reciprocal space, for comparison with experimental data from monochromatic Laue photographs.