We here study fragmentation using a simulated annealing clusterization algorithm (SACA) with binding energy at a microscopic level. In an earlier version, a constant binding energy (4 MeV/nucleon) was used. We improve this binding energy criterion by calculating the binding energy of different clusters using a modified Bethe-Weizsäcker mass (BWM) formula. We also compare our calculations with experimental data of the ALADiN group. Nearly no effect of this modification is visible.