Ab initio study of the structure and stability of MnTln (M = Cu, Ag, Au; n = 1, 2) clusters

The small coinage-metal thallium compounds MTl and M2Tl2 (M = Cu, Ag, and Au) are studied at HF, MP2 theoretical level with relativistic pseudopotentials. It is found that the butterfly structure with C2v (1A1) symmetry for M2Tl2 (M = Cu, Ag, and Au) is more stable than planar structures and the Au2Tl2 is the most stable cluster. The atomization energies and the HOMO-LUMO gap are evaluated, which indicates that doping clusters M2Tl2 are more stable than the pure clusters M4. The electron correlation effects on geometrical structures are investigated which compact and stabilize the present species. Theoretical results of the structure and the bond lengths for Au2Tl2 are in good agreement with experimental results available.