The development of accurate electronic structure theory for large systems and its application to interface systems

本研究的目的是为大规模系统，特别是由活性分子部分和给活性分子提供环境的背景组成的界面系统开发一个精确的电子结构理论和程序包。1.大系统电子关联方法的发展，特别是基于多参考(MR)的微扰理论(PT)；2.大系统相对论方法的发展；3.包括电子关联和相对论方法在内的有效程序包的开发；4.大系统电子结构和化学反应的研究.1.在电子相关方法中，精确和有效的方案是必不可少的.利用多参考扰动格式，我们发展了具有优化哈密顿划分的多组态扰动理论和具有最大…的扰动理论更多的会聚半径。2.对于包含重原子的大尺度系统，除了电子关联效应外，相对论效应也是重要的。我们发展了四组分多参考微扰(相对论GMC-QDPT)和组态相互作用(CI)方法。这些方法已经在从头算程序包UTChemo中实现。4.利用这些电子关联和相对论方法，我们已经对包括大分子体系在内的分子进行了如下应用：最稳定的硅碳团簇结构，层状无机化合物矿化的模板效应，长多烯的电子结构，氨选择性催化还原NO，花菁染料的结构和电子激发态，甲基乙烯基醚被OH自由基氧化的反应，二酮的光解离反应，过渡金属水合物的激发光谱，以及N-混杂卟啉的激发态性质。较少

The aim of the present research was to develop an accurate electronic structure theory and a program package for large-scale systems, especially for the interface systems which consist of an active molecular part and the background giving environment to the active molecule. The focus was especially on the following topics : 1.Development of electron correlation methods for large-scale systems, in particular a multireference (MR) based perturbation theory (PT), 2.Development of relativistic methods for large-scale systems, 3.Development of an efficient program package including the electron correlation and relativistic methods, and 4.Studies on the electronic structure and chemical reaction of large-scale systems.1.In the electron correlation method, an accurate and efficient scheme is essential. Utilizing the multireference perturbation scheme, we have developed a multiconfigurational perturbation theory with optimized Hamiltonian partitioning and a perturbation theory with the maximum … More radium of convergence. We have also presented Kohn-Sham DFT method with non-orthogonal localized orbitals.2.In addition to the electron correlation effect, the relativistic effect is also important for the large-scale system including heavy atoms. We have developed four-component multireference perturbation (relativistic GMC-QDPT) and configuration interaction (CI) methods. Relativistic Gaussian basis sets for the use of these MRPT and MRCI methods were also proposed.3.The methods have been implemented into an ab initio program package, UTChem.4.With these electron correlation and relativistic methods, we have made the following applications to molecules including large-scale systems : the most stable structure of silicon-carbon clusters, templating effects on the mineralization of layered inorganic compounds, the electronic structure of long polyenes, the selective catalytic reduction of NO by ammonia, the structure and electronic excited states of merocyanine dyes, the chain oxydation reactions of methyl vinyl ether by OH radical, the photodissociation reaction of diketones, the excitation spectra of transition metal aqua complexes, and the excited state properties of N-confused porphyrin. Less