采用优选的B3P86密度泛函方法,对铀原子和氮原子分别使用相对论有效原子实势和6-311+G(d)基组,研究了铀本身产生自辐射场(-0.005-0.005a.u.)作用下UN基态分子的能隙、谐振频率和费米能级。结果表明:UN分子在自辐射场中的谐振频率与实验值1 007.7cm^-1基本吻合。能隙和费米能级随自辐射场的增大而增大,占据轨道的电子难以被激发至空轨道而形成激发态,UN分子在自辐射场中更趋于稳定,可阻止N2等分子扩散到表面内层而腐蚀铀表面,有利于铀在自辐射场中抗腐蚀。
The density functional method DFT/B3P86 with relativistic effective core potential basis for U and 6-311+G(d)basis for N was used to study the energy gap,harmonic frequency,and Fermi energy level of ground state UN molecule under different inner radiation fields ranging from-0.005 to 0.005 a.u.The results show that the harmonic frequency is close to experimental value 1 007.7cm^-1 under different inner radiation fields.The energy gap and Fermi energy level are found to increase with the inner radiation field.The electron of occupied orbital is difficult to stimulate to empty orbital and to transform into excited station.The UN molecular is more stable in inner radiation field,so it can prevent N2 and so on to proliferate to superficial inner layer and then corrode the uranium surface,which contributes to the uranium corrosion prevention in inner radiation field.