The dissociation energy, equilibrium internuclear distance, and spectroscopic constants for the (1)Sigma(+)(g) ground state of the Yb(2) molecule are calculated. The relativistic effects are introduced through generalized relativistic effective core potentials with very high precision. The scalar relativistic coupled cluster method particularly well suited for closed-shell van der Waals systems is used for the correlation treatment. Extensive generalized correlation basis sets were constructed and used. The relatively small corrections for high-order cluster amplitudes and spin-orbit interactions are taken into account using smaller basis sets and the spin-orbit density functional theory. (C) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 111: 3793-3798, 2011