在相对论有效原子实势近似下,以Pu为SDD基组、0为6-311+G*基组,采用优选的密度泛函B3LYP方法,研究了用电场摸拟钚本身产生自辐射场(-0.005—0.005 a.u.)作用下氧化钚(PuO)基态分子的最高占据轨道(HOMO)能级E_H、最低空轨道(LUMO)能级E_L、能隙E_g和费米能级E_F.结果表明:在所加的电场范围内,E_H随着电场的增加均逐渐减少,E_F随着电场的增加均逐渐增大,E_g始终处于增大的趋势,费米能级E_F上升,占据轨道的电子难以被激发至空轨道而形成激发态,PuO分子在自辐射场中更趋于稳定,可以阻止O_2,H_2等扩散到表面内层而腐蚀钚表面,有利于了钚在自辐射场中抗腐蚀.
A density functional method DFT/B3LYP with SDD basis for Pu and 6-311+G~* basis for O is used to study HOMO energy level, LUMO energy level,energy gap,and harmonic frequency of PuO ground state molecule under different inner radiation fields ranging from—0.005 to 0.005 a.u..The results show that the magnitude and the direction of the electric field have important effects on these characteristics of PuO molecule.The HOMO energy level is found to decrease,but the LUMO energy level,energy gap and Fermi energy level are found to increase with the increase of electric field.The electron which occupies orbital is difficult to stimulate to empty orbital and transform into excited state.The PuO molecule is more stable in inner radiation field,and it can prevent O_2,H_2 and so on from proliferating to superficial inner layer and corroding the plutonium surface,which contributes to the plutonium corrosion prevention in inner radiation field.