Ab Initio Study of Structure and Stability of M2Al2 (M = Cu, Ag, and Au) Clusters

Coinage metal aluminium clusters M2Al2 (M = Cu, Ag, and Au) were studied by Hartree–Fock (HF) and second-order Møller–Plesset perturbation theory (MP2) with pseudopotentials. It was found that the butterfly structure with C2v (1A1) symmetry is more stable than the planar structure, and Au2Al2 is the most stable of the title species. The binding energies and the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO–LUMO) gap are evaluated, which indicates that doping clusters M2Al2 are more stable than the pure clusters M4 (M = Cu, Ag, and Au). Electron correlation and relativistic effects stabilize the present species.

Ab initio study of small coinage metal telluride clusters AunTem (n, m = 1, 2)

The geometries of the most stable isomers of gold telluride systems AuTe, Au2Te, and AuTe2 are determined using the MP2 method. The aspect of gold—telluride interaction, the electron correlation, and relativistic effects on geometry and stability are investigated at the MP2 and CCSD(T) theoretical levels. The results show that the electron correlation and relativistic effects are responsible not only for gold—gold attraction but also for additional gold—telluride interaction. The gold—telluride interaction is strong enough to modify the known pattern of bare gold clusters. Both effects are essential for determining the geometry and relative stability of this type of systems.