Knowledge Bank

Results of ab initio unrestricted Hartree-Fock self-consistent field and Meller-Plesset perturbation theory calculations for the hydrogen peroxide cation are reported. A $6-31G\ast \ast$ basis set was employed to compute energies on an extensive grid of nuclear configurations near the planar equilibrium geometry $(R\infty =1.32A,,ROH=1.00\backslash AA,\angle H\infty =104\circ )$. Analytical representations of potential energy and dipole moment surfaces were derived from least squares fits to the grid points and used to calculate spectroscopic constants, dipole moment expectation values and transition moments. A power series expansion to fourth degree in both normal and internal coordinates was used to obtain the spectroscopic constants, expectation values and intensities.