The equilibrium geometries, relative stabilities, and electronic properties of MnAgm(M=Na, Li; n + m ≤ 7) as well as pure Agn, Nan, Lin (n ≤ 7) clusters are systematically investigated by means of the density f...The equilibrium geometries, relative stabilities, and electronic properties of MnAgm(M=Na, Li; n + m ≤ 7) as well as pure Agn, Nan, Lin (n ≤ 7) clusters are systematically investigated by means of the density functional theory. The optimized geometries reveal that for 2 ≤ n ≤ 7, there are significant similarities in geometry among pure Agn, Nan, and Lin clusters, and the transitions from planar to three-dimensional configurations occur at n = 7, 7, and 6, respectively. In contrast, the first three-dimensional (3D) structures are observed at n + m = 5 for both NanAgm and LinAgm clusters. When n + m ≥5, a striking feature is that the trigonal bipyramid becomes the main subunit of LinAgm. Furthermore, dramatic odd-even alternative behaviours are obtained in the fragmentation energies, secondorder difference energies, highest occupied and lowest unoccupied molecular orbital energy gaps, and chemical hardness for both pure and doped clusters. The analytic results exhibit that clusters with an even electronic configuration (2, 4, 6) possess the weakest chemical reactivity and more enhanced stability.展开更多
基金Project supported by the Doctoral Education Fund of the Education Ministry of Chain (Grant No. 20100181110086) and the National Natural Science Foundation of China (Grant Nos. 11104190 and 10974138).
文摘The equilibrium geometries, relative stabilities, and electronic properties of MnAgm(M=Na, Li; n + m ≤ 7) as well as pure Agn, Nan, Lin (n ≤ 7) clusters are systematically investigated by means of the density functional theory. The optimized geometries reveal that for 2 ≤ n ≤ 7, there are significant similarities in geometry among pure Agn, Nan, and Lin clusters, and the transitions from planar to three-dimensional configurations occur at n = 7, 7, and 6, respectively. In contrast, the first three-dimensional (3D) structures are observed at n + m = 5 for both NanAgm and LinAgm clusters. When n + m ≥5, a striking feature is that the trigonal bipyramid becomes the main subunit of LinAgm. Furthermore, dramatic odd-even alternative behaviours are obtained in the fragmentation energies, secondorder difference energies, highest occupied and lowest unoccupied molecular orbital energy gaps, and chemical hardness for both pure and doped clusters. The analytic results exhibit that clusters with an even electronic configuration (2, 4, 6) possess the weakest chemical reactivity and more enhanced stability.