Reaction Ergodography for the Isomerizations of Methylenimine

The ab initio calcu lations have been performed on the reaction ergodography for the 1,2—H shift and inversion processes of methylenimine by the Intrinsic Reaction Coordinate（IRC） method. We have determined the potential energy surface and the transition state structures, and obtained the activation energies, activation entropies, frequency factors, tunnel effect coefficients and rate factors on the RHF/4-31G basis set. In addition, we have carried out the mode selective study on these two reaction processes. It suggested that the reaction coordinates （IRC） of 1,2-H shift and inversion processes be connected with the deformation modes of 1491 and 1192cm^-1 in the methylenimine, respectively.