Development of Molecular Theory for Molecular Design and Reaction Control

我们的目标是对包含数百个原子的系统发展精确的分子理论。我们的研究方向有三个：(1)发展新的从头算理论，特别是基于多参考的微扰理论；(2)发展包括相对论效应在内的分子理论；(3)发展密度泛函理论中的交换泛函和相关泛函。为了处理大系统，我们推导了基于准完全活动空间（QCAS） SCF波函数的微扰理论。从广义MC-SCF参考函数出发，提出了一种有效的摄动理论算法。我们提出了2分量RESC和高阶Douglas-Kroll (DK) hamilton算子。RESC和三阶DK。该方法可以很容易地结合到任何从头算和DFT理论中，并被证明是有效的、数值稳定的和可靠的。我们开发了一种求解四分量Dirac-Hartree-Fock和Dirac-Kohn-Sham方程的高效计算方案。在DFT研究中，我们提出了一个无参数交换泛函。最近，我们推导出了动力学、交换和相关泛函之间的横向物理联系。

We are aiming at developing accurate molecular theory on systems containing hundreds of atoms. We carried out our research in the following three directions : (I) development of new ab initio theory, particularly multireference-based perturbation theory, (ii) development of molecular theory including relativistic effects, and (iii) development of exchange and correlation functionals in density functional theory In order to treat large systems, we derived perturbation theory based on the quasi-complete active space (QCAS) SCF wave function. The efficient algorithm was developed for perturbation theory starting from the- general MC-SCF reference function. We proposed 2-component RESC and the higher-order Douglas-Kroll (DK) Hamiltonians. RESC and third-order DK. Methods can easily be incorporated into any ab initio and DFT theory, and proved to be efficient, numerically stable, and reliable. We developed a highly efficient computational scheme for solving 4-component Dirac-Hartree-Fock and Dirac-Kohn-Sham equations. In the DFT study, we proposed a parameter-free exchange functional. Recently we derived a transversing physical connection among kinetic, exchange, and correlation functionals.