摘要
应用Gaussian 98程序对U H2 O体系所有可能的构型进行优化计算 .采用密度泛函理论的B3LYP方法和MP2方法 ,对铀原子采用相对论有效原子实势及 (6s5p2d4f) [3s3p2d2f]收缩价基集合 ,氧、氢原子采用 6 311G 全电子基集合 .计算得到了 6种五重态的相对稳定结构的电子状态、几何结构、能量、谐振频率、力学性质和电性质等 .结果表明 ,H2 O蒸汽在金属铀表面的反应首先是铀和氧的相互作用 .对C2v相对稳定构型UOH2 (5A1 )的热力学稳定性进行了计算 ,其分解反应的Gibbs自由能ΔG°随温度的升高不断减小 。
In this paper, we study the relative stable molecular structures of uranium-water vapor system. For the uranium atom were used the relativistic effective core potential and contracted valued basis sets (6s5p2d4f)/[3s3p2d2f], and for oxygen and hydrogen atoms were used 6-311G** basis sets. We obtain the electronic state, geometric structure, energy, harmonic frequency, mechanical property, etc. of these six quintuple relative stable structures. It indicated that the first step of uranium-water vapor reaction is the interaction of uranium and oxygen atoms. The thermodynamical stability of UOH2 (5 A,) was calculated and its disassociation Gibbs free energy DeltaG(o)decreased with increasing temperature The result showed that low temperature favoured its existence.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第7期1617-1623,共7页
Acta Physica Sinica
