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.
出处
《贵州师范大学学报（自然科学版）》
CAS
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)
关键词
SIS
外电场
几何构型
基态
SiS
external electric field
geometry structure
ground state
