Ghazi Seyed Mohammad, Zorriasatein Shahab, Kanhere D G
Department of Physics and Center for Modeling and Simulation, University of Pune, Pune 411 007, India.
J Phys Chem A. 2009 Mar 26;113(12):2659-62. doi: 10.1021/jp809729p.
We have carried out extensive density functional calculations for series of sodium clusters NaN ranging from N = 10 to 147 and have obtained approximately 13000 distinct isomers. We unravel a number of striking features of the growth characteristics. The growth shows an order-disorder-order pattern of cyclic nature. Between two ordered clusters, the growth proceeds via disordered clusters having multicentered icosahedral local order. The global order emerges suddenly with the addition of one or two atoms only. The clusters around N = 92, the electronically closed shell system, behave completely differently and do not show the favored icosahedral local order. It is the absence of icosahedral local order that is responsible for the rather low melting temperatures observed in the experiments.
我们对钠簇NaN（N从10到147）系列进行了广泛的密度泛函计算，获得了约13000个不同的异构体。我们揭示了生长特性的一些显著特征。生长呈现出循环性质的有序-无序-有序模式。在两个有序簇之间，生长通过具有多中心二十面体局部有序的无序簇进行。仅通过添加一两个原子，全局有序就会突然出现。电子封闭壳层系统N = 92附近的簇表现完全不同，不显示出有利的二十面体局部有序。正是二十面体局部有序的缺失导致了实验中观察到的相当低的熔化温度。
