材料期刊网

The local meta-GGA exchange correlation density functional (TPSS) with a relativistic effective core potential was employed to systematically investigate the geometric structures, stabilities, and electronic properties of bimetallic Ca2Aun (n = 1-9) and pure gold Au-n (n <= 11) clusters. The optimized geometries show that the most stable isomers for Ca2Aun clusters have 3D structure when n > 2, and that one Au atom capping the Ca2Aun-1 structure for different-sized Ca2Aun (n = 1-9) clusters is the dominant growth pattern. The average atomic binding energies and second-order difference in energies show that the Ca2Au4 isomer is the most stable among the Ca2Aun clusters. The same pronounced even-odd alternations are found in the HOMO-LUMO gaps, VIPs, and hardnesses. The polarizabilities of the Ca2Aun clusters show an obvious local minimum at n = 4. Moreover, the inverse corrections to the polarizabilities versus the ionization potential and hardness were found for the gold clusters.