The development of quantitative molecular orbital theory for mesoscopic systems and its application to the initial chemical process of vision

从化学角度看，介观体系包括许多重要的体系，如溶质-溶剂体系、分子表面体系、扩展体系和团簇体系。本研究的目的是为介观系统建立定量的分子轨道理论和程序包，并将其应用于视觉的初始化学过程。会议的重点特别放在下列主题上：大型系统的多组态SCF和Kohn-Shem DFT方法的发展，2。2 .大系统电子相关方法的发展，特别是基于多参考的微扰理论MC-QDPT；大尺度体系的电子结构与化学反应研究。在从头算MO理论中，确定MO的有效方案至关重要。首先，我们开发了一种高效的分子积分算法和程序，这是MO测定必不可少的第一步，然后开发了QCAS-SCF、弦积空间SCF和通用MC-SCF方法。这些MC-SCF方法只处理化学上重要的电子构型，因此比传统的MC-SCF方法CAS-SCF方法更有效。我们还提出了大规模系统的Kohn-Sham DFT方法，使用非正交局域mos。为了包含电子相关效应，我们开发了QCAS-QDPT、gmmc - qdpt、mrpt -PT和MR-Brillouin-Wigner PT，这些PT是基于上一学期开发的紧致波函数，因此它们适用于大尺度系统。利用这些MC-SCF和微扰方法，我们在包括大尺度系统在内的分子中进行了以下应用：设计多电荷阴离子，分析CT化合物的中性离子跃迁，鉴定五元环化合物的高激发态，以及长多烯的电子结构。

The mesoscopic system includes many important systems, from chemical point of view, as solute-solvent systems, molecular-surface systems, extended systems, and cluster. The aim of the present research was to develop a quantitative molecular orbital theory and a program package for the mesoscopic system and to apply them to the initial chemical process of vision. The focus was especially on the following topics : 1. Development of multiconfiguration SCF and Kohn-Shem DFT methods for large-scale systems, 2. Development of electron correlation methods for large-scale systems, in particular a multireference based perturbation theory MC-QDPT, and 3. Studies on the electronic structure and chemical reaction of large-scale systems.1. In ab initio MO theory, an efficient scheme for determining MOs is crucial. First we have developed a highly efficient molecular integral algorithm and program, which is essential as the initial step of MO determination, and then developed QCAS-SCF, string-product space SCF, and general MC-SCF methods. These MC-SCF methods treat only chemically important electronic configuration and thus more effective than the CAS-SCF method, the conventional MC-SCF method. We have also presented Kohn-Sham DFT method for large-scale systems, using non-orthogonal localized MOs.2. For the inclusion of electron correlation effect, we developed QCAS-QDPT, GMC-QDPT, MROPT-PT, and MR-Brillouin-Wigner PT. These PTs are based on the compact wave functions developed in the previous term, and therefore they are applicable to large-scale systems.3. With these MC-SCF and perturbation methods, we have made the following applications to molecules including large-scale systems : Design of multiply charged anions, analysis of the neutral-ionic transition of CT compounds, identification of highly excited states of five-membered ring compounds, and electronic structure of long polyenes.