Trends in the structure and bonding of neutral and charged noble metal clusters

Abstract

AbstractWe present a systematic study of the electronic and geometric structure of neutral and charged noble metal clusters X (X = Cu, Ag, Au; n ≤ 13; ν = –1,0,+1), obtained from first principles GGA density functional calculations based on norm‐conserving pseudopotentials and a numerical atomic basis set. We determined that the maximum number of atoms forming planar structures with charge ν = (–1,0,+1) are (12, 11, 7) for gold, (5, 6, 5) for silver, and (5, 6, 4) for copper clusters. These results are compared with previous experimental and theoretical estimates. We argue that the tendency to planarity of gold clusters, which is much larger than in copper and silver, is strongly favored by relativistic effects, which decrease the s‐d electron promotion energy and lead to hybridization of the half‐filled 6s orbital with the occupied 5dz2 orbital. Trends for the calculated cohesive energy, average bond lengths, hardness (ionization potential minus electron affinity), and fragmentation energy of the X cluster are presented and discussed in comparison with available experiments and other calculations. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005