镎氧化物分子结构和光谱的理论研究

Theoretical Study on Molecular Structure and Spectrum of Neptunium Oxides

运用密度泛函理论(DFT)的B3LYP方法,优化了NpO,NpO_2,NpO_3和Np_2O_3分子的几何构型,分析了电子从Np到O的转移情况。结果表明:NpO,NpO_2,NpO_3和Np_2O_3的自旋多重度分别为6,2,2和9,对称性分别为C_(∞v),D_(∞h),C_(2v)和D_(3h)时相应分子处于稳定结构;对所有分子而言,分子能级在-50 eV左右的态主要由Np-6s轨道形成,在-20 eV附近的态主要由Np-6p和O-2s轨道混合组成,而大于-11 eV的态主要由Np-5f和O-2p轨道混合组成。同时,根据相关计算给出了分子基态结构的振动频率和光谱数据,并对红外光谱最大峰值的振动模式进行了指认。

The NpO, NpO2, NpOa and Np203 molecules geometric configurations have been optimized by using the B3LYP method of density functional theory （DFT）, and the information of the electron transfers from Np to O atoms has also been analyzed. The results show that NpO, NpO2, NpO3 and Np203 molecules stay in the stable structure when their spin multiplicities are 6, 2, 2 and 9, and symmetries are Cv, De.h, C2v and D3h, respectively; For all molecules, molecular orbitals were formed from Np-6s orbital when energy near -50 eV, formed from Np-6p mixture with O-2s orbitals when the energy near -20 eV, and formed from Np-5f mixture with O-2p orbitals when the energy greater than -11 eV. Meanwhile, the vibrational frequencies and spectral data of the ground state structure have been given. We also identified vibrational modes corresponding to the maximal peaks of infrared spectrum.