ISSN:
1600-5740
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
The static deformation electron density, Laplacian of the electron density and critical points in the electron density were analyzed in topaz Al2[SiO4]F2, using high-precision X-ray diffraction data. The electron deformation density, positive values of the Laplacian at (3,−1) bond critical points and the net atomic charges indicate a closed-shell-type interaction in the polyhedra. Anion valence-shell charge depletions are revealed. Maxima in the Laplacian of the electron density are displaced towards the close-packed plane owing to the mutual repulsion of the anion valence shells. The relationship between the topological features of the electron density and the close-packing concept is discussed. Shifts of the critical points from the internuclear vectors reflect the strain in the structure.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0108768198004108
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