An examination of UHF methods for atoms in the first three rows

The reliability and usefulness of UHF methods of calculating hyperfine parameters has been examined. Comparisons with CI and SEHF methods are made.A detailed analysis of OPHF calculations for first and second row atoms has shown that various one-electron properties are accurately described by physically reasonable functions of the atomic number Z. In addition there is a strong correlation between these properties. This has led to a method whereby UHF spin densities across a row of atoms can be obtained from UHF calculations of only two atoms in that row.A strong correlation between experimental and UHF spin densities is shown to exist for atoms of the first three rows. This is used to predict experimental spin densities for atoms in these rows which have not yet been measured experimentally.