摘要
铀原子和氧原子分别使用相对论有效原子实势（Relativistic Effective Core Potential）和6-311＋G（d）基组,采用优选的密度泛函B3P86方法,研究了铀本身产生自辐射场（-0.005～0.005 a.u.）作用下UO_3基态分子的最高占据轨道（HOMO）能级EH、最低空轨道（LUMO）能级EL、能隙Eg、费米能级FL和谐振频率ν.结果表明：UO_3分子在自辐射场中的谐振频率ν2（b1）、ν3（a1）、ν4（a1）和ν6（b2）与实验值151.5 cm-1、186.2 cm-1、745.7cm-1和852.6 cm-1基本吻合.EH随自辐射场的增加而减少,EL随自辐射场的增加而增大,Eg始终处于增大的趋势,费米能级FL上升,占据轨道的电子难以被激发至空轨道而形成激发态,UO_3分子在自辐射场中更趋于稳定,可以阻止O_2、H2等扩散到表面内层而腐蚀铀表面,有利于了铀在自辐射场中抗腐蚀.
A density functional method DFT/B3p86 with relativistic effective core potential basis for U and 6-311 ＋ G（d） basis forO has been used to study HOMO energy levels,LUMO energy levels,energy gaps,and harmonic frequencies of UO_3 ground state molecule under different inner radiation fields ranging from-0. 005 to0. 005 a. u.. The results show that the magnitude and direction of the inner radiation fields have important effects on these characteristics of UO_3 molecule. The harmonic frequencies ν2（b1）,ν3（a1）,ν4（a1） and ν6（b2） are close to experimental values 151. 5 cm-1,186. 2 cm-1,745. 7 cm-1and 852. 6 cm-1under different inner radiation fields. The HOMO energy level was found to decrease,but the LUMO energy level,energy gap and Fermi energy level were found to increase with increasing the inner radiation fields. The electron which occupies orbital is difficult to stimulate to empty orbital and transform into excited station. The UO_3 molecular is more stable in inner radiation fields,it can preventO_2、H2and so on to proliferate to superficial inner layer and corrode the uranium surface,which contributes to the uranium corrosion prevention in inner radiation fields.
出处
《原子与分子物理学报》
CAS
CSCD
北大核心
2016年第6期989-992,共4页
Journal of Atomic and Molecular Physics
基金
国家自然科学基金(11264020
11364023)
关键词
UO3
自辐射场
光谱
UO3
Inner radiation fields
Spectrum
