外场下SnO分子结构和特性研究  

SnO molecular structure and properties under external electric field

作　　者：黄多辉[1] 王藩侯[1] 袁娣[1] 

机构地区：[1]宜宾学院计算物理四川省高等学校重点实验室,四川宜宾644000

出　　处：《山东大学学报（理学版）》2014年第1期59-64,共6页Journal of Shandong University(Natural Science)

基　　金：四川省教育厅基金资助项目(13ZA0198)

摘　　要：对Sn原子采用SDB-cc-pVTZ基组,O原子采用6-311++G**基组,利用密度泛函中的B3P86方法对SnO分子的基态结构进行了优化计算,并研究了外场对SnO基态分子的键长、总能、电荷布居分布、能级分布、电偶极矩、谐振频率和红外谱强度的影响。并利用杂化密度泛函理论(CIS-DFT)方法研究了外电场对SnO分子由基态到前6个单重激发态跃迁规律的影响。结果表明,在所加电场范围内,随着正向电场F的逐渐增大,基态分子的键长R e先减小后增大,在F=0.04 a.u.时取得最小值0.179 6 nm;总能先增大后减小,其在F=0.03 a.u.时取得最大值-2 144.839 6 eV;电偶极矩则先减小后增大,在F=0.03 a.u.时取得最小值0.212 4 Debye;SnO基态分子的最高已占据轨道(HOMO)能量E H和谐振频率逐渐增大;红外光谱强度、分子的最低未占空轨道(LUMO)能量E L和能隙E g则逐渐减小。外电场的大小与方向对跃迁电偶极矩、跃迁波长、激发能和振子强度均有很大影响。The structure of SnO ground state molecule is optimized by employing density functional theory （B3P86） method with SDB-cc-pVTZ basis sets for Sn atom and 6-311 ＋＋ G for O atom. The effects of electric filed on the bond length, total energy, mulliken atomic charges, the Highest Occupied Molecular Orbital（HOMO） energy level, the Lowest Unoccupied Molecular Orbital （LUMO） energy level, energy gap, electric dipole moment, harmonic fre- quency and infrared intensity of SnO ground state molecule are studied. The excited properties of SnO molecule under different electric fields are also investigated by using configuration interaction singles density functional theory （ CIS- B3P86） method. The results show that the bond length and electric dipole moment are found to firstly decrease, then increasing with increasing of positive direction electric fields, the minimums are 0. 179 6 nm at F = 0. 04 a.u. and 0. 212 4 Debye at F =0. 03 a. u. , respectively. The total energy is proved to firstly increase, then decreasing with in- creasing of positive direction electric fields, the maximum is - 2 144. 839 6 eV at F = 0. 03 a. u.. The En and harmonic frequency are found to increase with increasing of positive direction electric fields, but the EL, Eg and infrared intensity are decreasing. The magnitude and direction of the external electric field have important effects on excitation energies, oscillator strengths and the wavelength.

关 键 词：SNO 外电场 激发特性 

分 类 号：O65[理学—分析化学]