Using the frequency-dependent dipole polarizabilities calculated for the five lowest states 2 S-1, 2 P-3, 2 P-1, 3 S-3 and 3 S-1 of Be and for the 2 S-2 and 2 P-2 states of Li, from our time-dependent gauge invariant method, estimates of C-6 were obtained for all the first molecular states dissociations: 2 S-1 + 2 S-1, 2 S-1 + 2 P-3, 2 S-1 + 2 P-1 and 2 P-3 + 2 P-3 of Be-Be and 2 S-2 + 2 S-1, 2 P-2 + 2 S-1 and 2 P-2 + 2 P-3 of Li-Be. Some higher interactions between these states were also estimated: 2 S-1 + 3 S-1, 3 S-3 + 2 P-3, 2 P-1 + 2 P-1, 3 S-1 + 2 P-1, 3 S-3 + 3 S-3, 2 P-1 + 2 P-3, and 3 S-1 + 3 S-1 for the homonuclear system, 2 P-2 + 2 P-1 and 2 S-2 + 2 P-3 for the heteronuclear one. Experimentally, only the (X (1)Sigma(g)(+)) ground state, and the two first (A (1)Pi(u) and B (1)Sigma(u)(+)) states, which dissociate in 2 S-1 + 2 S-1 and 2 S-1 + 2 P-1 channels respectively, are known for Be-2. The long-range coefficients reported for almost all of the low-lying states are new.