No abstract

Fifteen methyl-, nitro-, or mixed substituted N-(phenyl)-2-chloroacetamides were investigated by

A time-dependent approach is employed in conjunction with a crystal potential model to study the environment-specific optical linear response of the O 2-ions in a number of cubic oxides with varying number of constituents, unit-cell dimension and degree of complexity. It is shown that the static polarizability of the anion may vary significantly depending on the position of the anion within the unit-cell. Due to neglect of overlap compression, our method has limited success in predicting the refractive indices of large crystals of complex structures. For small binary oxides the frequency-dependent polarizability of the 0 :~ ion is found to exhibit the first poles close to the ultraviolet absorption edges ascribed to the lowest excitonic transitions in these crystals.

The electric field gradient (EFG) at the nuclei of the 5 sp impurities In, Sn, Sb, I and Xe in Cd metal is investigated on the basis of supercell band structure calculations of C d 15M (M = I n , . . . , Xe). The theoretical results show the same trend as the experimental findings. The differences in the EFG for different impurities are related to the charge distribution and partial densities of states.

The nuclear quadrupole interaction of *3Na and llB in NaBF, is investigated between 23 and 260 "C using single crystals and crystalline powder respectively. At 23 "C the folbwing results are found: e2 q Q/h (ZJNa) = 1008.4 kHz; e2 q Q/h ("B) = 59.9 kHz; r] (Na) = = 0.