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利用 Gaussian-94计算程序 ,B3 LYP方法 ,6-3 1 1 + G( 2 d) 6d基组 ,对 Si OM( M=Li,Be,B,Na,Mg,Al)诸体系的几何结构进行优化 .结果表明 ,M既可与 Si O中的 Si键合 ,也可与 O键合 .第一和第二主族的Si OM体系以折线形构型为最稳定构型 ,而第三主族则以近直线形或直线形构型为最稳定构型 .从 Si— O间键长 RSi O、力常数 f Si O及自然键轨道分析可知 ,第一主族的 Si OLi和 Si ONa的最稳定构型中 Si O— M间的离子键成分较大 ,可近似看作离子键 ;而对 Si OLi,Si OBe,Si OB和 Si OMg体系的以 Si为中心的构型 ,M— Si O间的离子键成分很小 ,不能看作离子键 ,可认为 M与 Si O之间存在着弱相互作用
The geometrical structures of Si OM (M = Li, Be, B, Na, Mg, Al) systems were characterized using the Gaussian-94 calculation program, the B3 LYP method and the 6-3 1 1 + G (2 d) The results show that M can bond with Si in SiO or with O. The Si OM system of the first and the second main groups are in the most stable configuration with a meander line configuration and the third main The near-linear or straight-line configuration is the most stable configuration.From the Si-O bond length RSi O, the force constant f Si O and natural bond orbital analysis shows that the first main group Si OLi and Si ONa most In the stable configuration, the ionic bond of Si-M is larger and can be approximated as an ionic bond. For the Si-centered configuration of Si OLi, Si OBe, Si OB and Si OMg systems, M-Si O Ion bond between the composition is small, can not be regarded as ionic bond, M and Si O can be considered that there is a weak interaction between