TOWARDS AN ACCURATE GOLD CARBONYL BINDING-ENERGY IN AUCO- BASIS-SET CONVERGENCE AND A COMPARISON BETWEEN DENSITY-FUNCTIONAL AND CONVENTIONAL METHODS( )

The binding energy of the ground-state AuCO+ molecule has been systema tically investigated using quantum chemical methods such as various de nsity functionals and correlated wave function based approaches like, second order Moller-Plesset perturbation and the coupled cluster ansat z with perturbative treatment of triple excitations, These were combin ed with a total of 14 relativistic effective core potential/valence an d all-electron basis sets of increasing flexibility for gold and CO, r espectively, Special emphasis is paid to the role of the basis set sup erposition error and the relevance of different ways to improve the on e particle basis sets, A significant effect on the basis set superposi tion error is observed in the density functional schemes upon enlargin g the valence basis sets, (C) 1998 American Institute of Physics. [S00 21-9606(98)02110-2].