The Coupled-Cluster Method is applied to calculate in two ways the detachment energies of Li⁻ and Be. In the first method we calculate the total energy of the atom and the corresponding ion and take the difference. In the second method the detachment energy is calculated directly. The first method gives good agreement with experiment but it is found that, if diagrams are included in a balanced manner, the second method seems more attractive. We have also studied the geometrical properties of the two outer electrons. Comparison of the two systems shows that the angular correlation is almost the same in both systems and is quite important while the radial correlation is much larger in Li⁻ than in Be. Both systems have a little tendency to have the electrons on opposite side of the atom (the average angle between the electrons is approximately 110°).