Significant nonadiabatic effects in the S(1D)+HD reaction

A nonadiabatic quantum dynamics calculation involving four coupled potential energy surfaces (two degenerate (3)A' ', one (3)A', and one (1)A') and the spin-orbit coupling matrix for these states is reported for the title reaction. The results show that the important discrepancy between theoretically calculated and experimentally measured intramolecular isotope effects can at least in part be attributed to significant nonadiabatic effects.