Variational transition-state theory study of the D− + H2 → HD + H− reaction and the H− + D2 → HD + D− reaction

In the present paper, the variational transition-state theory (VTST) method has been used to carry out the dynamical calculations for the D− + H2 → HD + H− reaction and the H− + D2 → HD + D− reaction, respectively. The investigation of the variation of the potential energy curves and the bond length with the reaction coordinate for the title reactions shows that the variational effect is negligible, while the tunneling effect is important. The above investigation also shows that the kinetic isotope effects (KIEs) are pronounced, which is in accordance with the experimental data and the theoretical investigation. In the following, the comparison of the rate coefficients calculated by TST, μVT and μVT/SCT methods also proves that the variational effect is negligible but the tunneling effect and the kinetic isotope effects (KIEs) are significant. Subsequently, the present μVT/SCT rate coefficients are comparable to the quasi-classical trajectory (QCT) results at higher temperature, while are generally smaller than the QCT ones over the considered temperature range for both the D− + H2 → HD + H− reaction and the H− + D2 → HD + D− reaction, respectively.