外电场作用下SiS分子结构及其特性研究  

Study on the molecular structure and properties of SiS in the external electric field

作　　者：罗琴[1] 宋晓书[1] 

机构地区：[1]贵州师范大学物理与电子科学学院,贵州贵阳55001

出　　处：《贵州师范大学学报（自然科学版）》2010年第2期99-103,共5页Journal of Guizhou Normal University：Natural Sciences

基　　金：贵州省科学技术基金(黔科合J字[2008]2232号);贵州省优秀科技教育人才省长基金(黔省专合字(2008)27号)

摘　　要：采用密度泛函B3P86/6-311++g(d,p)方法研究了在不同外电场(-0.03～0.03a.u.)作用下SiS基态分子的几何结构、能级分布、能隙、红外光谱及势能曲线等的变化规律。结果表明:随外电场(Si→S方向)的增大,SiS分子键长逐渐增大,分子振动频率和红外光谱强度逐渐减小,总能量逐渐升高,当F=-0.01a.u.时,能量达到最大,随后继续增大电场强度系统总能量开始降低;EH和EL及能隙随电场的增加逐渐增大,当F=0.02a.u.时,EH和EL及能隙均达到最大值,随着电场的继续增大,能级EH和EL及能隙逐渐减小;基态分子势能曲线对外电场方向有明显依赖关系。A The density functional theory（DFT） B3P86/6-311 ＋ ＋ g（d,p） method has been used to study the equilibrium geometry, energy levels, HOMO-LUMO gaps, infrared spectrum and the poten- tial energy curve of the ground states of SiS in different external electric fields ranging from -0.03 to 0. 03a. u. The results show that the molecular bond length gradually increases, but the molecular frequencies and IR intensity gradually decrease with increase of the external field along the molecular axis Si→S. As the electric field increased to -0.01a. u. , the total molecule energy reaches the maximum. Further increase of the electric field results in a decrease of the total energy. As the electric field increased to 0.02a. u. , the HOMO energy level, LUMO energy level and HOMO-LUMO gaps reaches the maximum. Then the HOMO energy level, LUMO energy level and HOMO-LUMO gaps gradually decrease with increase of the external field. The potential energy curve of the ground states of SiS molecule arestrongly dependent on the direction of external field.

关 键 词：SIS 外电场 几何构型 基态 

分 类 号：O56[理学—原子与分子物理]