title: Tunneling splitting of energy levels and rotational constants in the vinyl radical C2H3.
abstract: The instanton theory newly implemented by two of the authors (G.V.M. and H.N.) is applied to hydrogen tunneling transfer in a vinyl radical. The converged instanton trajectory is found on the CCSD(T)/aug-cc-pVTZ level of an ab initio potential energy surface. The calculated ground-state energy splitting agrees with the recent high-resolution experimental data within 3% of discrepancy. The semiclassical wave function is used to estimate the splitting of the principal rotational constants of the radical.
authors.affiliation: Department of Theoretical Studies, Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan.
authors.forename: Gennady V
authors.initials: GV
authors.lastname: Mil'nikov
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Ishida
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nakamura