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.