(CuAu_3)_n和(Cu_3Au)_n(n=1～15)团簇基态能量和结构的Monte Carlo模拟研究

Ground energy and structures of (CuAu_3)_n and (Cu_3Au)_n(n = l～15) studied by the Monte Carlo method

本文采用Monte Carlo方法和Gupta势函数对(CuAu_3)_n和(Cu_3Au)_n团簇的基态能量和结构进行了模拟研究,通过计算平均结合能、结合能的一阶差分和二阶差分,分析了团簇的稳定性.结果表明:(Cu_3Au)_n和(CuAu_3)_n团簇都为立体结构,都是以二十面体为基础形成的;(Cu_3Au)_n和(CuAu_3)_n团簇结构中金原子都有位于团簇表面的倾向;这两类团簇结构的区别在于:在(Cu_3Au)_n团簇中,铜一金原子混合程度高;而(CuAu_3)_n团簇中,形成金原子位于表层,铜原子位于中心的层状结构;且当n=3、5、7、9时,(Cu_3Au)_n和(CuAu_3)_n团簇在各自的序列中相对稳定性较邻近团簇高,特别是n=7的团簇,相对稳定性最高.

The Monte Carlo and Gupta potential were employed to investigate the ground energies and structures of（CuAu3 ） n and （Cu3 Au） n （n = 1 - 15） clusters. The binding energies, average binding energies, the first difference and second difference in the binding energy are calculated and discussed. It is showed that （CuAu3） n and （Cu3 Au） n （n= 1 - 15） clusters found to stereo construction, and the structures of clusters are primarily based on icosahedral packing. In the （CuAu3）n and （Cu3Au）n clusters, the gold atoms tend to lie on the surface of the cluster. The main difference between the two types of structure is that a more mixed arrangement of atoms is found in （CuaAu）n whereas the layers are formed for （CuAu3）n The （Cu3Au）. and （CuAu3）. clusters with sizes of n= 3,5,7 and 9 are more stable than those of the adjacent clusters of self sequence, and especially （Cu3Au）7 and （CuAu3）2 cluster are relatively most stable.