%AStewart, R F [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Chemistry]
%D1977
%I;
%JActa Crystallogr., Sect. A; (Denmark)
%K36 MATERIALS SCIENCE, BERYLLIUM, CHARGE DENSITY, BRAGG REFLECTION, CHEMICAL BONDS, DATA, DISTRIBUTION FUNCTIONS, ELECTRONIC STRUCTURE, LEAST SQUARE FIT, MONOCRYSTALS, VALENCE, X-RAY DIFFRACTION, ALKALINE EARTH METALS, COHERENT SCATTERING, CRYSTALS, DIFFRACTION, ELEMENTS, INFORMATION, MAXIMUM-LIKELIHOOD FIT, METALS, NUMERICAL SOLUTION, REFLECTION, SCATTERING, 360102* - Metals & Alloys- Structure & Phase Studies
%PMedium: X; Size: Pages: 33-38
%TCharge-density study of crystalline beryllium
%XThe X-ray structure factors for crystalline beryllium measured by Brown (Phil. Mag. (1972), 26, 1377) have been analyzed with multipole deformation functions for charge-density information. Single exponential radial functions were used for the valence charge density. A valence monopole plus the three harmonics, P/sup 3//sub 5/(cos theta) sin 3phi, P/sub 6/(cos theta) and P/sup 3//sub 7/(cos theta) sin 3phi, provide a least-squares fit to the data with Rsub(w)=0.0081. The superposition of these density functions describes a bonding charge density between Be atoms along the c axis through the tetrahedral vacancy. The results reported here are in qualitative agreement with a recent pseudo-potential calculation of metallic beryllium. The final residuals in the analysis are largest at high sin theta/lambda values. This suggests that core charge deformation is present and/or anharmonic motion of the nuclei is appreciable.
%0Journal Article
Denmark 10.1107/S0567739477000096 Journal ID: CODEN: ACACB INIS English