团簇V_3B_2成键及磁学性质研究

Bonding and Magnetic Properties of Cluster V_3B_2

为深入研究团簇V_3B_2中成键方式及磁学性质,基于密度泛函理论(density functional theory,DFT)B3LYP/Lanl2dz水平对团簇V_3B_2进行全参数优化,对优化构型的轨道杂化和电子结构进行了系统的研究。基于总态密度及分波态密度的分析发现团簇V_3B_2所有存在的稳定构型中,V—B键的形成主要是V-3p、V-3d、B-2p的p-d-p杂化,与文献报道的p-d杂化及s-p-d杂化有所不同,且进一步的研究发现B-2p、V-3d、V-4s的p-d-s杂化及B-2s、V-4s的s-s杂化也对该键的形成有一定贡献,至今未见文献报道。基于轨道自旋态密度的磁性分析表明B的掺杂导致了团簇磁性的下降,团簇磁矩基本上是由V-3d轨道中未成对电子贡献。

For the in-depth study of the bonding and the magnetic properties of V3B2 cluster,the hybridization of orbitals and the electronic structures of the optimized structures are studied systematically with the whole parameter optimization of cluster V3B2 under the level of DFT B3LYP/Lanl2 dz.The analysis of the total density of states and partial density of states show that the formation of the V-B bond is mainly from the p-d-p hybrid from V-3p,V-3dand B-2p in all existing stable configuration of cluster V3B2,rather than the p-d hybrid or the s-p-d hybrid as reported.A further study shows that the p-d-s hybrid from B-2p,V-3dand V-4sas well as the s-s hybrid from B-2sand V-4s,also have contribution to the formation of the V-B bond,which is not reported before.Magnetic analysis based on the spin state density shows that the B-doping leads to the decrease of the magnetic properties.The magnetic moment of cluster is basically contributed by the unpaired electrons in the V-3dorbit.