Kamiya Muneaki, Taketsugu Tetsuya
Faculty of Regional Studies, Gifu University, Gifu, 501-1132, Japan.
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.
J Comput Chem. 2019 Jan 15;40(2):456-463. doi: 10.1002/jcc.25727. Epub 2018 Nov 19.
Ab initio molecular dynamics approach has been extended to multi-state dynamics on the basis of the spin-orbit coupled electronic states that are obtained through diagonalization of the spin-orbit coupling matrix with the multi-state second-order multireference perturbation theory energies in diagonal elements and the spin-orbit coupling terms at the state-averaged complete active space self-consistent field level in off-diagonal elements. Nonadiabatic transitions over the spin-orbit coupled states were taken into account explicitly by a surface hopping scheme with utilizing the nonadiabatic coupling terms calculated by numerical differentiation of the spin-orbit coupled wavefunctions and analytical nonadiabatic coupling terms. The present method was applied to the A-band photodissociation of methyl iodide, CH I + hv → CH + I ( P )/I* ( P ), for which a pioneering theoretical work was reported by Amatatsu, Yabushita, and Morokuma. The present results reproduced well the experimental branching ratio and energy distributions in the dissociative products. © 2018 Wiley Periodicals, Inc.
基于自旋轨道耦合电子态，从头算分子动力学方法已扩展到多态动力学。这些自旋轨道耦合电子态是通过对自旋轨道耦合矩阵进行对角化得到的，对角元素采用多态二阶多参考微扰理论能量，非对角元素采用态平均完全活性空间自洽场水平的自旋轨道耦合项。通过表面跳跃方案明确考虑了自旋轨道耦合态之间的非绝热跃迁，该方案利用了通过自旋轨道耦合波函数的数值微分计算得到的非绝热耦合项和解析非绝热耦合项。本方法应用于碘甲烷的A带光解离，CH₃I + hv → CH₃ + I(P)/I*(P)，Amatatsu、Yabushita和Morokuma曾报道过关于此的开创性理论工作。本研究结果很好地重现了解离产物中的实验分支比和能量分布。© 2018威利期刊公司。
