Ab initio calculations on excited states of VCH

The ground state and various excited states of triplet and singlet VCH have been calculated using ab initio multiple reference configuration interacti on (MRCI) methods. The ground state is calculated to be a (3)Delta state ar ising predominantly from the single electron configuration .. 8 sigma(2) 3 pi(4) 9 sigma(1) 1 delta(1) with a calculated V-C bond length of 1.7061 Ang strom and a V-C stretching frequency of 837 cm(-1), which are in excellent agreement with experiment. The first excited state is the corresponding iso configurational low spin state,(1)Delta, which lies 4670 cm(-1) above the g round state. Higher excited triplet states are found to correlate well with experimentally known states. (C) 2000 Elsevier Science B.V. All rights res erved.