A quantum chemical study on chemical bonding of the doped clusters Si3M (M=Sc-Zn)
Abstract
A quantum chemical calculations and natural bond orbital (NBO) analysis at the B3P86/6-311+G(d) level of theory are carried out for the Si 3 M (M=Sc-Zn) cluster series, resulting in geometrical structures, stability and revealing the nature of their chemical bondings. All of the clusters exist in three structural forms at different spin states. The global minima of most clusters are 3M-1, three exceptions happen for M=Ti, Co, Ni. The Si 3 Co and Si 3 Ni clusters have the global minima of 3M-3. Remarkably, the Si 3 Ti cluster has the lowest-energy isomer of 3M-2, and it is also the most stable cluster in the series due to its stable electronic structure and highest Si-Ti bond order. There is a n electron transfering from AO-4s of M to silic on frame . The NBO analysis results in a polar covalent nature of the Si-M bonds which are mainly formed by the overlap between AO-3d(M) and AO-3s, 3p of Si atoms. The qualitative analysis of the MOs found that the Si-Ti in Si 3 Ti is of sigma and pi bond.