SAC-CI方法研究甲基乙烯基硅酮分子激发态1 ~1A″,1 ~1A′,2 ~1A″结构与性质  

Structure and properties of excited states 1 ~1 A″,1 ~1A′ and 2 ~1A″ of methyl vinyl siloxane molecule by SAC-CI method

作　　者：徐国亮[1] 谢会香[1] 王克栋[1] 王国志[2] 刘玉芳[1] 张现周[1] 朱正和[3] 

机构地区：[1]河南师范大学物理与信息工程学院,新乡453007 [2]许昌学院电气信息工程学院,许昌461000 [3]四川大学原子与分子物理研究所,成都610065

出　　处：《原子与分子物理学报》2011年第3期379-384,共6页Journal of Atomic and Molecular Physics

基　　金：河南省基础与前沿技术研究计划项目(092300410249);河南省高等学校青年骨干教师资助计划项目(2009GGJS-044);河南省教育厅自然科学研究计划(2010A140008)

摘　　要：采用对称性匹配簇/组态相互作用(symmetry adapted cluster-configuration interaction,SAC-CI)方法,在6-311++g^(**)基组水平上优化了甲基乙烯基硅酮分子的前三个单激发态1~1A",1~1A',2~1A"的平衡几何结构,比较三个激发态的电荷分布,最高占据轨道,最低空轨道,能隙等结构特性.研究发现,1~1A'态能隙差最小,电子容易发生跃迁.计算了三个单重激发态相应的振动光谱,得出其振动模式.从甲基乙烯基硅酮分子激发态结构特性,电荷分布,极强位置振动模式等方面分析了其断键机制.The equilibrium geometries of the first three singlet excited states 11A″,11A′,21A″of methyl vinyl silicone molecule are calculated using the general-R method of symmetry adapted clusterconfiguration interaction（SAC-CI） with 6-311＋＋g＂ basis set. The differences of structure parameters between the first three singlet excited states are compared. And then some property parameters of the first three singlet excited states 11A″,11A′,21A″ of methyl vinyl silicone molecule, such as charge distribution, highest occupied molecular orbital, HOMO, lowest unoccupied molecular orbital, LUMO, energy gaps etc. are investigated on the basis of having got stable structures of the three singlet excited states. The energy gap of 11A＇ state is found to be the smallest and the electrons of HOMO are more apt be excited. The corresponding vibration spectra of the three singlet states are calculated, and the vibration modes are obtained. In addition, the broken bonds mechanism of methyl vinyl silicone molcule on excited states is also analyzed, which are in better agreement with the experimental results.

关 键 词：甲基乙烯基硅酮 激发态 SAC—CI 振动光谱 老化机理 

分 类 号：O561[理学—原子与分子物理]