The electron excited states of a molecule play an important role in many areas of chemical and physical processes such as the electron and energy transfers in the light harvesting systems, photo-chemistry reaction and absorption, emission spectra of molecules etc. For small molecular studies, the high-level multi-reference correlation theories such as MRCI and MRPT2 are regarded as most reliable methods and have be intensively used in such field. However, it is not easy to develop an efficient MRCI/MRPT2 program. This lecture will report our new progress on developing the internal contracted MRCI (icMRCI) based on graphical unitary group approach (GUGA).  For medium or large molecules, TDDFT is already used as a workhorse because it is much computational efficient. However, UTDDFT from UKS reference state suffers from the spin-contaminated problem in studying the open-shell molecules due to the incomplete configuration space generated from single excitation. We have developed a spin-adapted TDDFT method to solve such problem. Here, several open shell transition metal compounds are calculated via SA-TDDFT and icMRCI that illustrates SA-TDDFT can give reliable result if some well-known limitations of TDDFT are avoided carefully.

报告人简介：索兵兵于1999年本科毕业于西北大学物理系，随后进入西北大学现代物理研究所攻读硕士学位，从事数学物理和场论的研究。从2002年9月起，索兵兵进入西北大学现代物理研究所攻读博士学位，期间致力于空穴粒子对应的图形酉群MRCI程序的开发及并行化工作。2005年7月到2006年12月，索兵兵赴美国加州州立大学东湾分校(California State University–East Bay)数学与计算机科学系访问，从事III-V族半导体团簇和过渡态金属化合物的电子结构，激发态和光谱性质的研究。自2007年3月起，索兵兵在西北大学现代物理研究所工作。2010年1月，加入北京大学化学与分子工程学院刘文剑教授领导的BDF研究组，负责基于高斯积分的量子化学程序研究与开发工作。目前的主要工作有：多参考态电子相关理论；线性标度的电子相关理论与算法；原子与分子激发态、光谱；高性能计算在量子化学中的应用等。