镍小团簇中金属键的E L F和L O L函数研究

用非限制性密度泛函方法UBP86泛函结合def2-TZVP基组获得了Ni2～6团簇的几何结构并用ELF(ElectronLocalized Function)和LOL(Localized Orbital Locator)函数对小镍团簇的电子结构进行拓扑分析.研究结果表明,除Ni2团簇外,团簇中Ni—Ni键的成键临界点不在键轴上,为弯曲键.镍团簇中Ni—Ni间的金属键为部分共价键,其价层Basin的布局数均小于1e,并且团簇中存在多个多中心价层Basin.团簇中各个化学键均强烈离域化.团簇中的单电子主要位于内层轨道,并没有参与成键.

ELF and LOL Studies on Metallic Bonds in Small Nickel Clusters

The ground state structures of small nickel clusters(Ni2~6) were investigated at the UBP86/TZVP level,and topological analyses of their electronic structures were performed with electron localized function(ELF) and localized orbital locator(LOL).The computational results predicted that the Ni—Ni bonds in the Ni3~6 clusters were bended because their bond critical point was not situated on the bond axis.The Ni—Ni metallic bond appeared to be a partial covalent bond which was often multicentric and was characterized by a low population of the valence basins(less than 1.0 e) and by synaptic orders as large as 4.The Ni—Ni bond was predicted to be strongly delocalized.The spin single electron of the clusters was mainly located in the C(Ni) basin,and did not participate in the formation of the Ni—Ni bond.