Theoretical study of the electronic spectrum and ESR of the CH2OH radical

The structure of the CH2OH radical was optimized at the UHF, UB3LYP, and MP 2 levels. The calculated ionization potential was very close to the experim ental one. The transition dipole moments from the ground state to the first four lowest excited states were calculated with and without C,symmetry usi ng the multireference single and double configuration interaction method (M RSD). The first four lowest excited states were also optimized with the sin gle excitation configuration interaction method (CIS). The adiabatic excita tion energies and transition dipole moments for vertical emission were calc ulated at the same level. None of these calculations lead to the assignment of the first excited Rydberg p state as (2)A " (3p(z) as suggested in a re cent paper (Chem. Phys. Lett. 318, 393, 2000). Some results of multireferen ce perturbation theory are also presented. The isotropic hyperfine paramete rs calculated with MRSD were in good agreement with the experimental values .