摘要
采用密度泛函(DFT)方法B3LYP/Gen,在Pu为相对论有效原子实势(RECP)基组、O为6-311+G*基组水平上优化得到了分子轴方向不同电偶极场(-0.005~0.005 a.u.)作用下,PuO3的基态电子状态为C2v(X^7B2)。在优化构型下用同样的基组采用含时密度泛函(TDDFT)方法(TD-B3LYP)研究了同样外电场条件下对PuO3的激发能和振子强度的影响。计算结果表明,激发能随电场强度增加而减小,表明在外电场作用下电子容易激发,且对电场方向的依赖呈现近似对称性,满足G rozem a关系。PuO3的前5个激发态电子跃迁光谱波长为900.2~2 063.3 nm,属于红外-远红外光谱,这是钚原子的奇异特征。电场对振子强度的影响仍满足跃迁选择定则。
The ground states of PuO3 under different electric fields ranging from-0.005 to 0.005 a.u.have been optimized using density functional theory DFT/B3LYP with RECP for Pu and 6-311＋G^＊ for O.The excitation energies and oscillator strengths have been calculated under the same electric fields employing the time-dependent DFT method.The results show that the electronic state and excitation energy are strongly dependent on the field strength of applied electric field.The total energy of the ground state decreases linearly with the applied field strength.The dependence of the calculated excitation energies on the applied electric field strength is fitting well to the relationship proposed by Grozema.The excitation energies of the first five excited states of PuO3 decrease as the applied electric field increases because the energy gap between the HOMO and LUMO become close with the field,which shows that the molecule is easy to be excited under electric field and hence can be easily dissociated.The spectra of the first five excited electron of PuO3 are in the region of far infrared.The wavelength is in 900.2~2 063.3 nm.
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第1期49-52,共4页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
国家自然科学基金资助项目(10965002)
江西省教育厅科技资助项目(GJJ10540)
