Configuration Interaction in the Simple Nonionic Valence-Bond Wavefunction for the H2I2 Reaction Complex

Abstract

The symmetry‐adapted MO configurations contained in the simple nonionic VB wavefunction for the H₂I₂ system in the H₂+I₂ and 2HI diatomic limits and in the $C_{\text{2v}}$ complex at the semiempirically determined saddle point are identified and their relative weights obtained as a function of the iodine orbital parameters. Implications of the results with regard to attempts to estimate the potential barrier height at the saddle point and to the mechanism of the hydrogen–iodine exchange reaction are discussed.