Ab initio calculations of electronic and vibrational energies of HCO and HOC

The ab initio calculation of electronic energies for numerous configurations of HCO and HOC, and a novel method for fitting the energies to a global surface are reported. This surface is used to calculate all the bound vibrational states of nonrotating HCO and DCO using the Watson Hamiltonian. Some quasibound vibrational states are also reported for nonrotating HOC for energies below the HOC saddle point energy. Comparisons of the HCO and DCO vibrational energies are made with recent experimental results.