Investigation On Geometrical And Electronic Structures Of The Closed-Packed Noble Metal Clusters By Density Functional Theory

In recent years, clusters have attracted much attention to science and technology. We systematically investigated geometrical and electronic structures of 13-atom close-packed noble metal clusters by density functional theory. VBP was chosen for the M@Cu12 and M@Ag12 (M=Hf~Hg) systems. However, VBP gave big error for bond length in the M@Au12 (M=Hf~Hg) case. Thus, we applied a new approach which chose Xαto optimize the geometry structures and VBP to calculate the energy, expressed as VBP//Xα.It was found that there was little difference of binding energies between the Ih and Oh isomers in the M@Cu12 and M@Ag12 systems. However, it was surprising that that Oh clusters were more stable than their Ih isomers except the W@Au12 in the M@Au12 systems. These results were contrary to the viewpoint that Ih clusters were more stable than their Oh isomers in the 13-atom cases which were suggested by many literatures.Pyykko and Runeberg theoretically predicted a rather stable cluster, namely, the Ih W@Au12. However, it was found that the Ih W@Au12 wasn't the most stable cluster in the M@Au12 system. Similarity existed for the M@Cu12 and M@Ag12 systems.