(CdSe)_6在外电场下的基态性质和红外光谱特性研究

Study on the ground state properties and infrared spectra of (CdSe)_6 in different external electric fields

以SBKJC为基组,采用PBE方法研究了不同外电场(0 a.u.～0.020 a.u.)对(CdSe)_6团簇的基态几何结构、电荷分布、能量、电偶极矩、HOMO能级、LUMO能级、能隙的影响,及其红外光谱特性随电场的变化情况。研究结果表明:当电场从0 a.u.变化到0.020 a.u.时,分子在电场方向被拉长,分子偶极矩逐渐增加,体系总能量一直减小,最低谐振频率逐渐减小;随着电场的增加,(CdSe)_6分子的LUMO能级降低,能隙减小;外电场对分子红外光谱特性有较大影响,如最强吸收峰的移动,导致一些新的较强吸收峰出现。

Based on SBKJC,the effects of different external electric fields (0 a.u.~0.020 a.u.) on the ground state geometry,charge distribution,energy,electric dipole moment,HOMO level,LUMO level,and energy gap of (CdSe) 6 clusters are studied by PBE method.The results show that the electric dipole moment is proved to be increasing with the increase of external field.However,the total energy,LUMO energy,energy gap and lowest harmonic frequency are found to decrease with the increase of external field.The external electric field has significant influence on the infrared spectra of (CdSe) 6 molecule,for example,the external electric field can lead to more infrared peaks and shift the strongest peak.