Structure And Stability Of Aluminum Sulfur And Aluminum Oxygen Binary Clusters

In recent years, with the development of clusers study, the dopedcluster has attracted widespread attention. The structures andproperties of clusters have obvious changed because of the dopedatom. So, people expect to uncover the formation mechanism andthe stability rule of the doped clusters theoretically, and providesome theoretical basis and guidance for performance and appliedmaterials.In this paper, The geometric configurations and electronicstructures of the AlnSm（n=1–10,m=1,2） clusters were studied usingthe B3LYP （Density Functional Theory, DFT） method at 6-311G**level. And we have discussed the ground state structure, chargetransfer and molecular orbital of the aluminum—sulfur dopedcluster. The results show that the ground state of AlnS （n>1）clusters were formed by adding S atom in different positions ofcorresponding Alnclusters. Al_nS₂（n<6） clusters were thecombination of two smaller Al_xS （x<n） fragments shared with Alatom, while clusters （n≥6） were formed by combining two S atomsand Al clusters. The molecular orbitals were mainly composed of Als- and p-states mixed with S p-states. These AlnS（n=1 10） clusterswith even n were more stable than those odd n by analyzing the energy of the ground state structure. AlnS2（n<6） clusters with even nare more stable, while the situation of AlnS2（n>6） clusters with odd 9was more stable.The structures and stability of AlnS±（n=1 10） was studiessystematically by density functional theory. The results indicatethat the ground state of AlnS±（n≤3） clusters are linear or planarstructures, while other AlnS±were the combination of one S atomand Al cluster. We found that AlnS+（n = 2, 3, 9） and AlnS （n = 1, 5, 8）clusters were more stable through the calculation of HOMO LUMOenergy gap and the second difference in cluster total energies.Density functional theory at the B3LYP level with 6-311G（2d）basis sets have been carried out on the structures and stability ofAlnO±（n=2 10） clusters. The geometric structures, energies,vibrational frequencies, dissociation energies and the seconddifference in cluster total energies. We found that O atom tended toeither be inserted between Al atoms or be absorbed at the surfaceof the Al clusters to form an Aln-1OAl. The ground state of AlnO±clusters were the combination of one Al2O or Al3O fragments and Alcluster shared with Al atom. The coordination numbers are 3 and 4for most Al atoms and 2 and 3 for most O atoms. Dissociationenergies and the second difference in energies implied that AlnO+（n= 2, 5, 7, 9） and AlnO （n = 2, 4, 7, 8） clusters possess relativelyhigher stability.