The electronic structure of the beryllium dimer Be-2 was investigated at valence Full-Configuration-Interaction (FCI) level, using a large cc-pV6Z basis set, (7s6p5d4f3g2h1i). This gives a total of 280 contracted Gaussian functions for the dimer, corresponding to a valence FCI space of about 185 x 10(6) symmetry-adapted Slater determinants. The adiabatic potential energy curves of the singlet ground X-1 Sigma(+)(g) and the triplet lower excited (1)(3)Sigma(+)(u) states were calculated, and the principal spectroscopic constants for the two states were evaluated. Our results are found to be very close to recent experimental values published in the literature. (C) 2013 Elsevier B.V. All rights reserved.