在相对论有效原子实势近似下,用B3LYP密度泛函方法计算优化得到了分子轴方向不同电场(-0.005~0.005a.u.)作用下,PuO的基态C∞V(X7-)几何结构、偶极矩和分子总能量。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PuO的激发能的影响。计算结果表明,在外场作用下,对PuO的前5个激发态电子跃迁光谱属于远红外光谱,波长为2 064.7~18 900.0nm,这是钚原子的奇异特征;激发能与外电场的关系近似满足Grozema等人提出的关系。
The ground states of PuO under different electric fields ranging from -0. 005 to 0. 005 a. u. have been optimized by using density functional theory DFT/B3 LYP with Gen for Pu and 6- 311 + G for O. The excitation energies have been calculated under the same electric fields employing the time-dependent DFT method. The results show that the electronic state, total energy, molecular geometry, dipole moment and excitation energy are strongly dependent on the field strength of applied electric field. The dependence of the calculated excitation energies on the applied electric field strength is fitting well to the relationship proposed by Grozema. The spectra of the first five excited electron of PuO are in the region of far infrared. The wavelength is in 2 064.7-18 900.0nm.