铜簇Cu_n^-和羰基铜簇Cu_nCO^-(n=2～7)的结构与光谱性质的密度泛函理论研究

Density Functional Theory Study of Structures and Spectroscopic Properties of Cu_n^- and Cu_nCO^-(n=2-7)

应用相对论有效核势密度泛函理论计算方法研究了 Cu- n 和 Cun CO-簇的平衡几何构型、稳定性、主要碎片化模式、CO吸附能及其团簇的光谱性质 .计算结果表明 ,奇数簇 Cu- n 的电离势比其相邻偶数簇 Cu- n 的电离势大 ;奇数的 Cu5CO- 簇有最大的 CO解离能 .奇数铜簇阴离子相对较高的稳定性与近似浆汁模型的 8电子电子闭壳层效应一致 .计算得到的 Cu- n 簇碎片化能量表明 ,较小 Cu- n 的优势解离通道与其包含 Cu原子数目的奇偶性有关 ,偶数的 Cu- n 簇主要解离为 Cu原子和 Cu- n- 1 ,而奇数 Cu- n 簇易以解离成铜的二聚物 Cu2和 Cu- n- 2 .基于密度泛函理论计算 ,讨论了这些簇的静态极化率和

Equilibrium geometries, stabilities, preferred fragmentation channels, CO adsorption features and spectroscopic properties of Cu - n and Cu n CO - were investigated by the density functional theory(DFT) combined with the relativistic effective core potentials. The calculated results show that the odd numbered copper cluster generally has a relatively higher ionization potential than the even numbered species, and CO dissociation from the odd Cu 5CO - requires the largest energy of 1.21 eV among such copper cluster monocarbonyls here. Such high stabilities of the odd copper cluster anions and Cu 5CO - are consistent with the closed shell effect within the jellium shell model approximation. B3LYP fragmentation energies reveal that the preferred dissociation channel of the odd numbered copper cluster anion is the loss of copper dimer Cu 2, while the loss of Cu is favored in energy for the even numbered copper cluster anion. On the basis of current DFT calculations, the size dependences of static polarizabilities and the features of CO adsorption on copper clusters were discussed.