Study of CH3− and OH3+ by One-Center Expansion Self-Consistent-Field Method

Abstract

Single‐determinant self‐consistent‐field wavefunctions calculated by the one‐center expansion method are reported for CH₃⁻ and OH₃⁺ molecules. The basis functions, symmetry adapted Slater‐type orbitals, were all centered at the heavy nucleus. In both cases a total of 25 basis functions were used. Both of these molecules were found to be nonplanar. For CH₃⁻, the equilibrium bond length and bond angle were found to be 2.028 bohr and 109°56′, respectively; for OH₃⁻, these quantities were calculated to be 1.918 bohr and 110°54′. The total energy of these molecules was found to be−39.3367 hartree for CH₃⁻, and −76.2330 hartree for OH₃⁺. A limited basis‐set calculation for planar OH₃⁺ using 17 symmetry adapted STO's is also reported. The total energy and bond length for this case are −76.1704 hartree, and 1.826 bohr, respectively. Some other interesting features of these calculations are discussed.