Abstract: The vibrations of Ru-terminal ligands (Q-mode) and intra-bridged ligand (6a mode) as well as their combination in the mixed valence Taube ion are studied by using density functional theory method under the Borh-Oppenheimer approximation. It is found that these three vibrations all are harmonic vibrations. And Q-vibration causes the charges on Ru1 and Ru2 atoms to be asymmetrical distribution. The charge transfer between Ru and terminal NH₃ ligands is responsible for this asymmetrical change in charges on Ru atoms. The 6a vibration of the bridged ligand increases the asymmetry of the charge distribution on Ru atoms. However, in the combinational vibration of Q- and 6a vibrations, the Q-component dominates the asymmetrical charge contribution on Ru atoms. The difference of the charge distribution on metal atoms between the Taube ion and Fe₂O₁₁ system is briefly discussed.

Key words: density functional theory, Taube ion, vibration mode, electron transfer

摘要： 在Borh-Oppenheimer近似下，应用量子化学的密度泛函理论方法研究了混合价Taube离子中金属与配体之间的振动(Q-振动模式)、桥配体内的振动(6a振动模式)以及这两种振动的组合。发现这三种振动模式都可以看成简谐振动。Q-振动使Rul和Ru2原子上的电荷发生不对称的分布，这种不对称分布来源于Ru和NH₃配体之间的电荷转移；桥配体的6a振动对Rul和Ru2原子上的电荷影响是对称的，在与Q-振动的组合中，桥配体的６a振动增加了Ru1和Ru2原子上电荷的不对称性分布。在这种组合中，Q-振动对Ru原子电荷分布起主导作用。文中简要地讨论了Taube离子中金属原子电荷分布与Fe₂O₁₁体系的差别。

关键词: 密度泛函, Taube离子, 振动模, 电荷转移