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利用密度泛函理论(DFT)总能计算研究了Ni(110)-p2mg(2×1)-CO表面的原子结构和电子态.计算结果表明:CO分子吸附于该表面的短桥位附近,分子吸附能为1.753eV,CO分子的键长dC—O为0.117nm,分子与表面竖直方向的夹角为20.0°,碳原子和短桥位中点的连线与竖直方向的夹角为20.9°;吸附的CO分子内原子间的伸缩振动频率为1876和1803cm-1.态密度研究结果表明吸附作用主要来自CO分子π、σ轨道与衬底d轨道间的杂化作用.CO分子σ轨道和衬底表面镍原子dxz轨道杂化形成的表面电子态主要位于费米能以下-10.4至-8.8eV和-7.4至-5.1eV范围内.σ和dxz轨道间的杂化作用可能是形成p2mg表面对称性的重要因素之一.
The atomic structure and electronic states of Ni (110) -p2mg (2 × 1) -CO surface have been calculated by the total energy density functional theory (DFT). The calculated results show that the CO molecules adsorbed near the short bridge site, The molecular adsorption energy is 1.753eV, the CO bond length dC-O is 0.117nm, the angle between the molecule and the vertical direction of the surface is 20.0 °, the angle between the connection point of the carbon atom and the middle point of the short bridge and the vertical direction Is 20.9 °, and the stretching vibrational frequencies of the adsorbed CO molecules are 1876 and 1803 cm -1 .The results of density of states show that the adsorption mainly comes from the hybridization between the CO orbitals and the orbitals of the substrate CO molecule Surface electron states formed by orbital hybridization of the nickel atom on the σ orbital and the substrate surface lie mainly in the range of -10.4 to -8.8 eV and -7.4 to -5.1 eV below Fermi energy.The hybridization between the σ and dxz orbitals may be Form p2mg surface symmetry one of the important factors.