MnAr(n-1,2；M=Cu、Ag、Au)分子的从头算研究

摘要

The geometric structures and stabilities of noble metals doped Ar mdecules MnAr(n - 1,2;M = Cu, Ag, Au) are studied at Ab initio study of the Hartree-Fock( HF) and M0ller-Plesset(MP2) theoretical levels, using rel-ativtistic pseudopotentials and the match basis set. The results show that molecular weak interaction between noble metal and Ar atom is very small, so it must be basis set superposition error ( EBSSE ) when the bonding energy is calculated. The clusters contained Au has the largest bonding energy, the strongest stability and the maximum gap energy , which contained Ag has the minimum gap energy and the strongest chemical activity. The electron correlation effects reduce M-Ar bond lengths significantly, but influences on bond lengths M-M and bond angles M-M-Ar are very small. The electron correlation effects reduce bond lengths,increase vibrational frequencies, decrease energies and make the clusters trend to more compact and more stable.%使用相对论赝式及相应的基组,在从头算(Ab initio)方法中Hartree-Fock (HF)、Mφller-Plesset(MP2)理论水平上研究贵金属与稀有气体氩掺杂所组成的MnAr(n=1,2；M=Cu、Ag、Au)分子体系的几何结构与稳定性.结果显示,贵金属与Ar原子之间相互作用较小,必须进行基组重叠误差修正EBSSE计算其结合能.含Au的分子体系的结合能最大,稳定性较强,能隙Egap最大,化学活性弱.含Ag的分子体系能隙最小,化学活性最强.电子相关效应对M-Ar的键长修正非常显著,而对M-M键长和M-M-Ar键角的修正很小,电子相关效应使键长缩短、振动频率提高、能量降低、使分子的结构更加紧密,使体系更加稳定.