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用量子化学从头计算(ab initio)方法,计算了U—O体系气态分子的优化几何构型、总能量、振动频率和成键情况,并构筑了该体系有关相互作用的势能面。计算的铀氧化物优化构型和振动频率同现有的实验数据符合较好。布居数分析结果表明在形成铀氧化物时,主要是U5f电子参加了与氧成键,但在UO和UO_3中,U6d轨道电子成键的成分相对于UO_2有所增大。同时,由于铀的7s和6d及5f轨道能量很接近,形成ds杂化轨道并参与成键。各氧化物的第一电离能同文献数据符合较好。势能面分析结果表明铀氧化产物取决于铀原子与O_2相互作用的方式。
By means of ab initio method, the optimized geometrical configuration, total energy, vibrational frequency and bond formation of gaseous molecules in U-O system have been calculated and the potential energy surface of the system has been constructed. Calculated uranium oxide optimization configuration and vibration frequency with existing experimental data in good agreement. The results of population number analysis show that U5f electrons mainly participate in oxygen bonding when uranium oxide is formed, but the content of U6d orbital electron bonding in UO and UO_3 increases relative to UO_2. At the same time, due to the very close orbit energy of 7s, 6d and 5f of uranium, ds hybrid orbital is formed and participates in bonding. The first ionization energy of each oxide is in good agreement with the literature data. Potential energy surface analysis results show that the uranium oxidation products depend on the way of uranium atoms interacting with O_2.