Relativistic Electronic Structure Theory and Its Applications to Chemical Reactions

1. 对于含有重原子的分子的电子结构计算，在哥伦布程序系统中制定并实现了高效的自旋轨道（SO）CI方法。为了高效计算，采用了酉群、时间反演对称性和双点群等各种群论。 SO相互作用已被纳入SCF和MCSCF方法中，并用于分析各种原子和阳离子中的LS和jj耦合方案。 2．采用SOCI方法研究了Cl_2分子的光解离，发现R=6 bohr附近的Rosen-Zener-Demkov型非绝热相互作用是导致产物分支比、各向异性参数和产物Cl(^2P_<1/2>)原子角动量j=l/2方向的量子力学干涉的波长依赖性的原因。 3．利用理论上获得的电子跃迁矩和L-解耦矩阵元，采用SOCI方法研究了O_2 Herzberg带的振动和旋转吸收强度。尽管强度非常弱，但仍获得了与实验数据相当好的一致性。对于各向异性参数，我们的数据支持Parker等人的实验结果。产物的支化率由长键距下的多级多步非绝热相互作用决定。 4．我们还对Icl、I^-_3、Xe I_2、HgCO、HgAr、镧系阳离子、过渡金属苯配合物等进行了理论研究。

1. For the electronic structure calculations for molecules containing heavy atoms, an efficient spin-orbit (SO) CI method was formulated and implemented in the Columbus program system. For the efficient calculations, various group theories, such as unitary group, time-reversal symmetry, and double point group have been employed. SO interactions have been included in the SCF and MCSCF methods and the programs have been used to analyze the LS and jj coupling schemes in various atoms and cations.2. Photodissociation of Cl_2 molecule has been studied with the SOCI method and a Rosen-Zener-Demkov type non-adiabatic interaction at about R=6 bohr was found to be responsible for the wavelength dependence of the product branching ratio, anisotropy parameter, and quantum mechanical interference of the orientation of angular momentum j=l/2 of the product Cl(^2P_<1/2>) atom.3. Vibrational and rotational absorption intensities of the O_2 Herzberg band have been studied by the SOCI method with the theoretically obtained electronic transition moments and L-uncoupling matrix elements. In spite of the very weak intensities, fairly good agreement with experimental data was obtained. As for the anisotropy parameter, our data support the experimental results of Parker et al. The branching ratios of the products were determined by the multi-level and multi-step non-adiabatic interactions at longer bond distances.4. We have also studied theoretically on Icl, I^-_3, Xe+I_2, HgCO, HgAr, lanthanide cations, and transition metal-benzene complexes and so on.