Electron density in Si 2 and Cl 2

Author： Mrozek Janusz Smith Vedene Salahub Dennis Ros Piet Rozendaal Alon

ISSN： 1362-3028

Source： Molecular Physics, Vol.41, Iss.3, 1980-10, pp. : 509-517

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Self consistent field-X molecular orbital calculations have been performed for Si 2 and Cl 2 using both the scattered-wave (SW) and LCAO discrete-variational (DV) versions of the method. For Si 2 an SW calculation including f partial waves yields orbital densities in good agreement with those from methods which do not involve the muffin-tin approximation for the potential. The present results afford a further comparison relevant to the recent discussion (see, M. Schlüter et al. [9]) of the relative accuracy of various pseudocharge densities compared with real charge densities. The deformation density from the X-SW calculation is in good agreement with that from the DV-X method and also with that from the linear muffin tin orbital method (J. Harris and R. O. Jones [8]). Differences between the valence electron distribution which is usually discussed in connection with pseudopotential schemes, and the density distribution including the 2 s and 2 p core electrons are delineated. For Cl 2 , the X-SW deformation density shows positive lobes along lines through the atoms perpendicular to the bond axis, is negative for most of the area between the atoms and also shows negative lobes behind the atoms. This deformation map is in good qualitative agreement with the DV-X map and also with recent ab initio results with the exception of a small region at the centre of the bond in which the DV-X and ab initio results show an excess of electrons compared with the promolecule whereas the X-SW results show a deficiency. Comparisons with X-ray results on solid chlorine are inconclusive so that experimental electron scattering data on gas phase chlorine will be required to resolve this difference.