Non-spherical atoms have been used to fit a variety of molecular densities. The aim is to develop a new atoms in molecules approach that will produce useful entities which may be used to determine the molecular properties in a straightforward manner. The theory has been developed from the work on Stewart atoms by Stewart! and Gill.2 The method follows the resolution of the identity approach developed by Gill and incorporates anisotropic basis functions into the determination of the constituent atoms. The non-spherical atoms have been applied to a variety of small molecules including H2 , N2 , HF and H20. Molecular properties such as the charge, dipole, quadrupole, nuclear attraction energy and electron repulsion energy have been determined. The results are encouraging and show that anisotropic fitting atoms provide a way forward for the atoms in molecules approach. An alternative fitting procedure has also be looked into. This breaks the resolution of the identity approach into two stages with the hope of creating smaller matrices and eliminating some of the numerical difficulties that have been encountered.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:489889 |
| Date | January 2007 |
| Creators | Young, Richard L. |
| Publisher | University of Nottingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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