Theoretical Study on the Photoreactions of Biological Compounds

我们的多参考Moller-Plesset （MRMP）理论是封闭壳单参考MP方法的扩展，已成功应用于许多化学和光谱问题。通过本研究，MRMP已成为处理动力和非动力相关效应的有效技术。MRMP应用于多烯、多烯和卟啉的价态π * π ^*激发态的研究。MRMP令人满意地描述了交替烃的低价位π * π ^*激发态的排序。MRMP预测价态激发能的精度为0.2 eV或更高。具有交替配对性质的MRMP方法在理解和预测交替烃类实验数据方面具有重要价值。本研究的结论在一定程度上是可转移的，从而为描述其他较大的多烯、多烯和卟啉的激发态提供了合理的基础。我们还提出了一个完整的活性空间价电子键（CASVB）方法。CASVB波函数可以通过对典型的CASSCF函数进行简单的变换得到，并且很容易用众所周知的经典VB共振结构来解释。CASVB提供了各种状态的波函数的清晰视图。此外，我们还提出了几个新的理论和概念：扩展基函数空间（EBS）中的MRMP，通过消除四分量Dirac方程的小分量（RESC）的新相对论格式的相对论MRMP。EBS-MRMP是一种基于不同基础的相关效应概念的理论。新的resc方案是狄拉克方法的一个很有前途的替代方案。我们还在密度泛函理论中提出了一种新的简化的collei - salvetti型相关泛函，称为OP。OP只有一个参数，没有可调整的功能常数。OP满足精确相关泛函的所有必要条件。证明了OP能给出更精确的原子相关能和G2组分子的等效化学性质。少

Our Multireference Moller-Plesset (MRMP) theory is an extension of the closed-shell single reference MP method and has been successfully applied to numerous chemical and spectroscopic problems. MRMP has established through this study as an efficient technique for treating both dynamical and nondynamical correlation effects. MRMP was applied to the study of the valence pi*pi^* excited states of polyenes, polyacenes, and porphyrins. MRMP satisfactorily describes the ordering of low-lying valence pi*pi^* excited states for alternant hydrocarbons. MRMP predicts the valence excitation energies with an accuracy of 0.2 eV or better. The MRMP approach with the alternant pairing properties has proved to be of great value in understanding and predicting the experimental data of the alternant hydrocarbons. The conclusion derived in this study is to some extent transferable and thus provides a reasonable basis for a description of the excited states of other larger polyenes, polyacenes and porphyr … More ins. We have also proposed a complete active space valence bond (CASVB) method. A CASVB wave function can be obtained simply by transforming a canonical CASSCF function and readily interpreted in terms of the well-known classical VB resonance structures. The CASVB affords a clear view of the wave functions for the various states. In addition, we have proposed several new theory and concepts : MRMP in the extended basis function space (EBS), relativistic MRMP with a new relativistic scheme by eliminating small-component (RESC) of the four-component Dirac equation. EBS-MRMP is a theory based on a concept of different bases for different correlation effects. The new RESC-scheme is a very promising alternative to the Dirac method. We have also proposed a new simplified Colle-Salvetti-type correlation functional called OP in density functional theory. OP includes only one-parameter and no adjusted functional constant. OP satisfies all the necessary conditions of the exact correlation functional. OP is proved to give more accurate correlation energies for atoms and equivalent chemical properties for G2 set of molecules. Less