第一性原理比较研究MnPm(M=Al,Ga,In,2≤n+m≤3)团簇

利用密度泛函理论对MnPm (M=Al,Ga,and In,2≤n+m≤3)团簇的几何和电子结构性质及稳定性进行了研究.结果表明,三原子的MnPm团簇是二重态,而单体则是三重态.富P的MP2团簇是具有C2V对称性的等腰三角形结构,而富M的M2P团簇则是具有Cs对称性的三角形结构.在三原子磷化物团簇中,MP2团簇比M2P团簇稳定,而后者中M-P键的强度比前者强.对于这些小的磷化物团簇,电离势高于裂解能,表明裂解比电离占优势.Ga2P比Al2P和In2P的HOMO-LUMO能隙和电离势都高,归咎于在富金属的M2P团簇中,相对较强的Ga-P键.

First principles comparative study of polyatomic clusters of MnPm (M=Al,Ga,and In,2≤n+m≤3)

The structural,electronic properties,and stability of MnPm (M=Al,Ga,and In,2≤n+m≤3) clusters have been investigated by density-functional theory.The results indicate that triatomic isomers prefer doublet spin states,whereas triplets are predicted for the monomer.The lowest energy structures of phosphorus-excess triatomic clusters are an isoceles triangle with C2V symmetry,and metal-excess triatomic clusters show minimum energy configurations to be a triangle with Cs symmetry.In the triatomic clusters,MP2 clusters are more stable than M2P clusters,while the Metal-P bond in the latter is stronger than that in the farmer.The calculated ionization potentials are larger than the fragmentation energies of these small phosphide clusters,exhibiting a dominance of dissociate over ionization.For M2P clusters,the HOMO-LUMO gap and ionization potential values of Ga2P are higher than those of Al2P and In2P,due to the relatively strong Ga-P bond in the metal-excess M2P clusters.