利用B3LYP杂化密度泛函方法,在相对论有效芯势模型下,优化得到了NpO_2~(2+)离子及其配合物在气相和水溶液中的几何结构和电子结构,研究了NO-3、SO2-4和CO2-3离子及其水溶液对NpO_2~(2+)离子的结构和性质的影响.结果表明,NpO_2~(2+)离子结合各种酸根离子后其Np=O键的键长都有明显增长、Np和O原子的价电子轨道能均有升高,而考虑溶剂化效应后酸根离子的影响将减小.电荷分析发现,结合酸根离子后,NpO_2~(2+)中Np和O原子间形成的共价键的强度减弱、键长增长.对NpO_2~(2+)离子与三种酸根离子的理论结合能的比较显示,Np O2CO3分子最为稳定. Using B3LYP hybrid density functional theory, the geometry and electronic structure of NpO_2 ~ (2+) ion and its complex in gas phase and aqueous solution were optimized under the relativistic effective core potential model. The effects of NO-3, SO2 -4 and CO2-3 ions and their aqueous solutions on the structure and properties of NpO_2 ~ (2+) ions were studied. The results showed that the bond lengths of Np = O bonds of NpO_2 ~ (2+) ions after binding various acid ions , The valence electron orbitals of Np and O atoms both increase, while the influence of acid ions will be reduced after considering the solvation effect.Characteristics of charge analysis show that Np and The covalent bond formed between O atoms weakened and the bond length increased.The comparison of the theoretical binding energies of NpO 2 2+ with three kinds of acid ions showed that the molecule of Np O 2 CO 3 was the most stable.