Structural exploration of Au(x)M(−) (M = Si, Ge, Sn; x = 9–12) clusters with a revised genetic algorithm

We used a revised genetic algorithm (GA) to explore the potential energy surface (PES) of Au(x)M(−) (x = 9–12; M = Si, Ge, Sn) clusters. The most interesting finding in the structural study of Au(x)Si(−) (x = 9–12) is the 3D (Au(9)Si(−) and Au(10)Si(−)) → quasi-planar 2D (Au(11)Si(−) and Au(12)Si(−)) structural evolution of the Si-doped clusters, which reflects the competition of Au–Au interactions (forming a 2D structure) and Au–Si interactions (forming a 3D structure). The Au(x)M(−) (x = 9–12; M = Ge, Sn) clusters have quasi-planar structures, which suggests a lower tendency of sp(3) hybridization and a similarity of electronic structure for the Ge or Sn atom. Au(9)Si(−) and Au(10)Si(−) have a 3D structure, which can be viewed as being built from Au(8)Si(−) and Au(9)Si(−) with an extra Au atom bonded to a terminal gold atom, respectively. In contrast, the quasi-planar structures of Au(x)M(−) (x = 9–12; M = Ge, Sn) reflect the domination of the Au–Au interactions. Including the spin–orbit (SO) effects is very important to calculate the simulated spectrum (structural fingerprint information) in order to obtain quantitative agreement between theoretical and future experimental PES spectra.