Woldeghebriel Hagos, Kshirsagar Anjali
Department of Physics, University of Pune, Pune 411 007, India and Department of Physics, Mekelle University, Tigray, Ethiopia.
J Chem Phys. 2007 Dec 14;127(22):224708. doi: 10.1063/1.2805388.
Results describing the interaction of a single sulfur atom with cationic gold clusters (Au(n) (+), n=1-8) using density functional theory are described. Stability of these clusters is studied through their binding energies, second order differences in the total energies, fragmentation behavior, and atom attachment energies. The lowest energy structures for these clusters appear to be three dimensional right from n=3. In most cases the sulfur atom in the structure of Au(n)S(+) is observed to displace the gold atom siting at the peripheral site of the Au(n) (+) cluster. The dissociation channels of Au(n)S(+) clusters follow the same trend as Au(n) (+) cluster, based on the even/odd number of gold atoms in the cluster, with the exception of Au(3)S(+). This cluster dissociates into Au and Au(2)S(+), signifying the relative stability of Au(2)S(+) cluster regardless of having an odd number of valence electrons. Clusters with an even number of gold atoms dissociate into Au and Au(n-1)(S)(+) and clusters with an odd number of gold atoms dissociate into Au(2) and Au(n-2)(S)(+) clusters. An empirical relation is found between the conduction molecular orbital and the number of atoms in the Au(n)S(+) cluster.
描述了使用密度泛函理论研究单个硫原子与阳离子金簇(Au(n) (+),n = 1 - 8)相互作用的结果。通过这些簇的结合能、总能量的二阶差分、碎片化行为和原子附着能来研究它们的稳定性。从n = 3开始,这些簇的最低能量结构似乎是三维的。在大多数情况下,观察到Au(n)S(+)结构中的硫原子取代了位于Au(n) (+)簇外围位置的金原子。基于簇中金原子的偶数/奇数,Au(n)S(+)簇的解离通道与Au(n) (+)簇遵循相同的趋势,但Au(3)S(+)除外。该簇解离为Au和Au(2)S(+),这表明Au(2)S(+)簇具有相对稳定性,尽管其价电子数为奇数。具有偶数个金原子的簇解离为Au和Au(n - 1)(S)(+),具有奇数个金原子的簇解离为Au(2)和Au(n - 2)(S)(+)簇。在Au(n)S(+)簇的传导分子轨道和原子数之间发现了一种经验关系。