Structural, Electronic Properties Of Au_n+1 And M@Au_n?n=2-8, M=Al,Si,P,S,Cl? Clusters: Density Functional Theory Study

Gold is a transitional precious metal, It can be formed trivalent and monovalent cations after the dissolution, it will not react with most chemicals chemically. Gold as good electrical,thermal conductivity, scalability and high density, soft, light merit, as well as anti-corrosion features, has been applied in electronic, communication, aerospace, chemical and medical technology field, extensively. Au clusters as transitional states between a single Au atoms and lump gold, which physical and chemical properties is not only different from the individual atoms, but also unlike bulk gold, it can be varied with atomic number change, generally.Recently, in order to optimize the structure and properties of gold clusters, the Au clusters of the incorporation of a transitional metal atom have been extensively studied, but the gold clusters incorporated 3p non-metal atom has been scant research. Therefore, the geometry clusters, relative stability and electronic properties of Au_n+1 and M@Au_n?n=2-8, M=Al, Si, P,S, Cl? clusters are investigated systematically in this paper.The initial geometry optimizations of the Au_n+1 and M@Au_n?n=2-8,M=Al, Si, P, S, Cl?clusters are adopted using DFT with the PW91 change-correlation functional and many isomers have been obtained. The results show that the ground state of Au_n+1 clusters tend to two-dimensional planar structure with the increasing number of Au atoms; For doped M@Au_n clusters, all non-metal atoms in the ground state structure of small clusters tend to occupy a significantly higher ligand for n=2-3.It is found from the results of atomic averaged binding energies that with the increasing number of Au atoms, the Eb of Au clusters and dopanted-clusters presents complex trends;The average binding energy of doped M@Au_n? 4? n?8,M=Al, Si, P, S, Cl? clusters is significantly less than gold clusters. For the second-order energy differences of the ground state clusters, Au_n+1?n=3,except?, M@Au_n?M=Al, P, S?clusters showed obvious parity oscillation characteristics, M@Au_n?n=2-4, M=Al, P; n=2-8, Si? and S@Au_n?n=5-7?clusters with the Au clusters of the ground state have the same parity oscillation trend; while the M@Au_n?n=5-7, M=Al, P;n=2-7, Cl? and S@Au_n?n=2-4?clusters appeared opposite oscillation.The analysis of energy gap showed that in addition to M@Au_n?n=5, 7,M=Si, P, S? clusters,the doped M@Au_n?n=2-8,M=Al-Cl?clusters compared to the Au clusters with the same atomic number, which increases the energy gap of Au cluster; Meanwhile, it can be drawn, It has a big contribution adulterating metal Al atomic ratio of non-metallic Si-Cl atomic to increase the energy gap of Au_n?n=3-5?clusters. However, it is more significantly to increase its energy gap,as Si-Cl atom than Al doping in Au₉ cluster.The results for dipole moment and the zero-point vibrational energy of the ground state clusters showed that Al and Si atoms doping in Au clusters had a significant impact to dipole moment and zero-point vibrational energy. whereas, the dipole moment of Al@Au_n, Si@Au_n clusters own an odd-even oscillation phenomenon,while, zero-point vibrational energy is gradually increasing. The analysis of rotational constants for Au cluster and doped clusters showed that doping has changed rotational constants,and the rotational constants of M@Au₄?M=Al-Cl? ground-state cluster presents oscillation.