相对论效应对巯基金团簇电荷分布的影响

在巯基金团簇中尤其是部分巯基包裹的金核簇,Au原子和S原子的电荷分布是决定金核簇静电势的重要因素.Au是有强相对论效应的重元素,相对论效应对裸露的和有机分子保护的金团簇的几何结构和电子结构有不可忽略的影响.基于密度泛函理论,运用第一性原理研究了环状Au4(SCH3)4簇的电子结构.结果表明相对论效应对电荷分布有重要影响.根据Hirshfeld和Mulliken这两种方法对电子数进行分析,发现当考虑相对论效应时几乎没有电荷从Au转移到S,而不考虑相对论效应时有大量电荷从Au转移到S.

The Impact of Relativistic Effect on the Charge Distribution in Thiolate-Au Clusters

In thiolate-Au clusters especially partially thiolates covered with core Au clusters,the charge distribution in Au and S atoms is an important factor which decides the electrostatic potentials of core Au cluster.The Au is a heavy element with strong relativistic effect.The relativistic effect has unnegligible impacts on the geometric structure and electronic structure of the bare and monolayer-protected Au clusters.In this paper,the electronic structure of cyclic-like Au4(SCH3)4 cluster is studied by the first-principles calculations based on density functional theory.The results indicate that the relativistic effect has significant impact on the charge distribution.According to the population analysis of both Hirshfeld and Mulliken method,there is little charge(electrons) transfer from Au to S when using relativistic effect treatment but large charge(electrons) transfer when nonrelativistic treatment is considered.