High-precision photon diffraction data in beryllium, diamond, silicon, copper and germanium are reanalysed with the aim of assessing the accuracy of experimental X-ray and gamma-ray structure factors by comparing derived values for cohesive energy with the thermochemical ones. Special attention is devoted to the diffraction data analysis for a meaningful and accurate comparison between theory and experiment. A good overall agreement of local density approximation calculations is found when the electron density exhibits spherical symmetry around each atomic site. On the contrary, the analysis of experimental data in 3d transition metals, namely vanadium, chromium, iron, cobalt and nickel, points out failures of the theory in reproducing the asphericity of the electron distribution.
Relevance of Charge-Density Measurements for High-Precision Calculations
PETRILLO, Caterina;SACCHETTI, Francesco;
1998
Abstract
High-precision photon diffraction data in beryllium, diamond, silicon, copper and germanium are reanalysed with the aim of assessing the accuracy of experimental X-ray and gamma-ray structure factors by comparing derived values for cohesive energy with the thermochemical ones. Special attention is devoted to the diffraction data analysis for a meaningful and accurate comparison between theory and experiment. A good overall agreement of local density approximation calculations is found when the electron density exhibits spherical symmetry around each atomic site. On the contrary, the analysis of experimental data in 3d transition metals, namely vanadium, chromium, iron, cobalt and nickel, points out failures of the theory in reproducing the asphericity of the electron distribution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
