Charge-density study of crystalline beryllium
Stewart, R F [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Chemistry]
36 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
The 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.
Denmark
1977-01-01
English
Journal Article
Journal Name: Acta Crystallogr., Sect. A; (Denmark); Journal Volume: 33:1
Medium: X; Size: Pages: 33-38
Journal ID: CODEN: ACACB
INIS; AIX-08-303057; EDB-77-082430
2010-12-30
7116563