金团簇Au_n(n=17-19)分子静电势的理论研究

Theoretical Study on the Molecular Electrostatic Potential of Aun(n=17-19)

在混合密度泛函BP86理论下,用LANL2DZ基函数对Aun(n=17-19)构型进行优化、电荷分布和分子静电势进行计算.结果表明:NPA和MK电荷能够很好的重现静电势的分布;Aun(n=17-19)电势分布的特点是最大正电势出现在五配位的金原子周围,最大负电势值出现六配位的金原子周围,它们组成了化学反应中最可能的活性点.

Density functional theory （DFT） calculations on Aun （n= 17--19） were carried out at the BP86/ LANL2DZ level. The optimized configurations, atomic charges and electrostatic potential distributions have been obtained. The calculated results show that the NPA and MK charges reproduce well the electro- static potential; a striking feature of the electrostatic potential of Au, （n= 17--19） is that the regions of the pentacoordinated Au atom are significantly positive and the vertex regions of the hexacoordinated Au atom are more negative. They constitute the most probable active sites in chemical reactions.