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采用平面波赝势方法,利用基于从头计算的软件包,对乙烯和乙炔基在Ni(110)表面上吸附的问题进行了计算.在低覆盖度时,孤立的乙烯分子的吸附能比密集时高,乙烯分子的C-C轴大致沿衬底的Ni原子链方向(即沿[11-0]晶向),C-C轴与衬底Ni(110)表面有12°的倾斜角,乙烯分子的C—C键的键长为0.147nm.乙烯分子中接近顶位的C原子与衬底中距离最近的Ni原子为0.199nm.在高覆盖度时,乙烯分子在Ni(110)表面上形成c(2×4)再构,每个表面二维元胞中有两个乙烯分子,每个乙烯分子的吸附位置与低覆盖度时相似,而C—C键长比低覆盖度时要短.乙炔基是乙烯在Ni(110)表面上分解的产物.关于乙炔基的计算结果表明乙炔基的两个C原子的间距为0.131nm,比乙烯分子中C原子的间距更短.与乙烯分子相比,乙炔基的吸附位置更靠近顶位.H原子与吸附在顶位上的C原子相连接,C—H键也大致沿衬底的Ni原子链方向,与Ni表面呈45°的倾斜角.
Adsorption of ethylene and ethynyl groups on the surface of Ni (110) was calculated using a plane-wave pseudopotential method based on ab initio software package. At low coverage, the isolated ethylene molecule has a higher adsorption energy than the dense , The CC axis of the ethylene molecule is approximately in the direction of the Ni atom chain of the substrate (ie, in the [11-0] crystal orientation), the CC axis has an inclination angle of 12 ° with the surface of the substrate Ni (110), C-C The bond length of the bond is 0.147 nm. The C atoms close to the top in the ethylene molecule are 0.199 nm away from the nearest Ni atom in the substrate. At high coverage, ethylene molecules form c (2 × 4) Reconstitution, with two ethylene molecules in each two-dimensional cell, with each ethylene molecule adsorbed at a similar location to the low coverage, while the C-C bond length is shorter than the low coverage The product of the decomposition of ethylene on the surface of Ni (110) The calculation of the ethynyl group shows that the distance between the two C atoms of the ethynyl group is 0.131 nm, which is shorter than the distance between the C atoms in the ethylene molecule.Compared with the ethylene molecule, The adsorption site of the group is closer to the top site, the H atom is connected to the C atom adsorbed on the top site, and the C-H bond is also generally along the chain of Ni atoms of the substrate , Of 45 ° and the inclination angle of the surface of Ni.