ScienceAsia 6 (1980): 178-182 |doi: 10.2306/scienceasia1513-1874.1980.06.178
OPTIMIZED GAUSSIAN EXPANSION OF ATOMIC ORBITALS
Summary: Property-optimized Gaussian expansions of Slater-type orbitals (STO) were used to calculate the ground state energy and the one-electron molecular properties of the water molecule and the NH2 species. The effect of simultaneously using a weighting
factor and pseudonormalization was studied. The weighting factor was seen to give a definite improvement: in the energy calculation, the weighting factor r-1 gives satisfac. tory results, i.e. the energy is improved by about 0.7 a.u. (from -72.78278 a.u. to -73.52642 a.u.) compared tq the un weighted expansion with STO-2G for the water molecule (at a bond angle of 105o). The weighting factor r1 gives an extremely good result in the dipole moment calculation. For the water molecule with STO-2G it is 0.5633 a.u. while the unweighted filting gives 0.4954 a.u. compared to the STO result
of 0.5642 a.u.
Department of Chemistry. Faculty of Science, Chulalongkorn University. Phya Thai Rd., Bangkok, Thailand.
Received 2 September 1980