No abstract

The integrated intensities samples were measured at of high order reflections from Cr powder 297, 505, 607, 708 and 806 K using MoKa ..radiation. The temperature dependence of the integrated intensities indicates significant anharmonic contributions, which are parametrized in terms of the effective one-particle potential, V(u) = +U' + 7u4, using quantum statistics. At 297 K, the values (9.27 f 0.37) eV A-' and -(12 f 3) eV A-4 are obtained for the isotropic harmonic and anharmonic potential parameters, respectively. For comparison, the harmonic parameter is calculated using the interatomic force-constants determined from inelastic neutron scattering. Comparison is also made between the classical and quantum approaches.

The thermal motion parameters, B, of the TI+ and C1-ions of TlCl are determined by X-ra diffraction from powder samples between 296 and 534 K.