Knowledge Bank

Ab initio calculations have been performed that generate the restricted Hartree-Fock wavefunctions and excitation energies for the ground state and lower excited states of the hydroxy $(OH\ast )$, methoxy $(CH30\ast )$, ethoxy $(C2H5O\ast )$, isopropoxy (C3H7O.). and vinoxy (C2H3O.) radicals. These theoretical results are compared to results obtained from laser-excitation spectra that were recorded in a supersonic free-jet expansion at low temperature for these radicals (Foster, Hsu, Liu, kung, and Miller). As anticipated, correlation-energy contributions to the excitation energies are small. The calculations provide assignments of the ground-state symmetry and energy splittings of the ethoxy and isopropoxy radicals, The resulting relative symmetries of the observed transitions are opposite to those obtained from the spectroscopic band assignments for these radicals.