BONDING ELECTRON-DISTRIBUTION IN SILICON

The bonding electron distribution in silicon is determined from X-ray data. The numerical analysis is based on the Pendellösung data by Aldred and Hart (Proc. Roy. Soc. London A332 (1973) 223) for the ‘conventional’ reflections and by Fehlmann and Fujimoto (J. Phys. Soc. Jpn. 38 (1975) 208) for the ‘forbidden’ (222) reflection. It is shown that an accurate (222) structure amplitude aids greatly in interpreting the ‘conventional’ reflections in terms of Dawson's general structure amplitude formalism. The bonding features can be described by two non-spherical scattering components plus a scalar deformation term (in the form of a radially contracted valence shell scattering amplitude). While the broad electron density features can be accurately determined, caution should be exercised in accepting the least-squares refined values for the Debye-Waller factor and for the anomalous dispersion (due to the high correlation between these parameters). © 1979, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.