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采用密度泛函理论中的广义梯度近似(GGA)对(MgO)nCu(n=2～8)团簇的几何构型进行优化,并对能量、频率和电子性质进行了计算.结果表明:(MgO)nCu的最低能量结构是在(MgO)n的最低能量结构或者亚稳态结构的基础上吸附一个Cu原子生长而成,且Cu原子的吸附以桥位为主.布局数分析表明Cu原子的吸附对近邻原子的电荷影响比较大,Cu原子得失电子的方向可以改变.Cu原子的吸附增强了(MgO)n的化学活性.二阶能量差分,垂直电离势和分裂能表明(MgO)4Cu是最稳定的团簇.
The geometrical configurations of (MgO) nCu (n = 2 ~ 8) clusters were optimized by using the generalized gradient approximation (GGA) in density functional theory and the energy, frequency and electronic properties were calculated. The lowest energy structure of MgO) nCu is formed by the adsorption of one Cu atom on the basis of the lowest energy structure or metastable structure of (MgO) n, and the adsorption of Cu atoms is dominated by bridging sites. The adsorption of Cu atoms enhances the chemical activity of (MgO) n. The second order energy difference, the vertical ionization potential and the cleavage energy show that (MgO) 4Cu Is the most stable cluster.