采用第一性原理研究了稀有气体原子在Pu(100)表面上的吸附。计算结果表明:除He原子外,其他稀有气体原子在桥位处的吸附能均为最大;稀有气体原子在Pu(100)表面吸附后,稀有气体原子失去电荷,而Pu原子得到电荷,稀有气体原子中Xe原子的电荷转移数最大。差分电荷密度的计算结果表明,对位于Pu(100)表面穴位和桥位处的Xe原子,可观察到较明显的电荷再分布现象,这表明Xe原子具有一定极化效应,能与Pu(100)表面发生相互作用,从He到Xe,原子的极化效应越来越明显。

The adsorption of rare gas atoms on Pu (100) surface was studied using the first-principles .T he results show that the adsorption energy is the largest w hen the rare gas atoms are in the bridge position except for He atom .Rare gas atoms lose electrons when they have been adsorbed on Pu(100) surface ,while Pu atoms gain electrons ,and the number of charge transfer is the largest for Xe atom .Difference electron density results show that for Xe atom in bridge and hollow position , distinct charge redistribution can be seen clearly , w hich show s that Xe atom can be more easily polarized and may have some reactions with the Pu (100) surface ,and polarization effect increases from He to Xe atom .

异种类型元素的混合极大地丰富了稀有气体团簇的性质，而确定具有弱相互作用力稀有气体团簇的结构是一项重要的任务。本研究采用三元Lennard-Jones (TLJ)势函数来描述Ar-Kr-Xe团簇原子间的相互作用。使用自适应免疫优化算法(AIOA)预测了 Ar25(KrXe)50团簇的最稳定结构。优化结果显示该团簇的最优结构类型为多四面体不规则结构和由4个双二十面体构成的环状结构。此外，通过归一化应变能的计算推测出Ar-Ar和Xe-Xe键对团簇结构影响最为明显。

The properties of noble gas clusters can be greatly enlarged by the mixtures of heterogeneous elements, and the structural optimization with weak interactions has become a significant problem in the area of theoretical chemistry. The interatomic interaction in Ar-Kr-Xe clusters is described by ternary Lennard-Jones (TLJ) potential. The stable structures of Ar25(KrXe)50 clusters are optimized by adaptive immune optimization algorithm (AIOA). Results show that there exist polytetrahedral structures and ring-like structures linked by four double icosahedra. Furthermore, the results show that the reduced strain energies are affected mainly by Ar-Ar and Xe-Xe bonds.