We present, for the first time, ab initio simulated molecular dynamics within the adiabatic approximation. The tests are made for H-2(+) and its isotopomers. We show that the farces on the nuclei can be calculated with sufficient accuracy to distinguish among the isotopomers. We also show that there are two regions where these forces are non-negligible, compared to those of Born-Oppenheimer: at large nuclear distances and near the equilibrium positions.