Persaud Rudradatt Randy, Chen Mingyang, Dixon David A
Department of Chemistry and Biochemistry, The University of Alabama, Shelby Hall, Tuscaloosa, Alabama 35487-0336, United States.
Center for Green Innovation, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
J Phys Chem A. 2020 Mar 5;124(9):1775-1786. doi: 10.1021/acs.jpca.9b11801. Epub 2020 Feb 20.
The geometries of the group 11 coinage metals ( = 2-20) were optimized to determine the lowest energy isomers for each cluster size, singlets for even numbers and doublets for odd numbers. For copper and silver, 2-D (planar) geometries were favored up to = 6. For gold, 2D (planar) geometries were favored up to = 13. Normalized clustering energies were plotted as a function of cluster size (, for = 4-20) with various DFT functionals and the CCSD(T)-F12b method and were extrapolated to predict the bulk cohesive energy. In the case of copper and silver, there is excellent agreement between the cohesive energies predicted at the CCSD(T)-F12b level of theory and the experimental values. For gold, the CCSD(T)-F12b values needed to be corrected for spin-orbit relativistic effects to obtain good agreement with experiment. Electronic properties including the HOMO-LUMO gaps for the even clusters and the spin densities for the odd clusters were calculated. The lowest gap is predicted to occur for = 16 where the HOMO and LUMO are very similar in shape.
对11族铸币金属（= 2 - 20）的几何结构进行了优化，以确定每种团簇尺寸的最低能量异构体，偶数团簇为单重态，奇数团簇为双重态。对于铜和银，直至 = 6时二维（平面）几何结构更受青睐。对于金，直至 = 13时二维（平面）几何结构更受青睐。使用各种密度泛函理论（DFT）泛函和耦合簇单双激发加微扰三重激发（CCSD(T)-F12b）方法，将归一化团簇能量作为团簇尺寸（ = 4 - 20时的）的函数进行绘制，并外推以预测体相凝聚能。在铜和银的情况下，CCSD(T)-F12b理论水平预测的凝聚能与实验值之间有很好的一致性。对于金，需要对CCSD(T)-F12b值进行自旋轨道相对论效应校正，以与实验取得良好一致性。计算了包括偶数团簇的最高已占分子轨道（HOMO）-最低未占分子轨道（LUMO）能隙和奇数团簇的自旋密度在内的电子性质。预测最低能隙出现在 = 16时，此时HOMO和LUMO的形状非常相似。
