The influence of two solvents, water and acetonitrile on the crystal habit of succinic acid is modelled using the build-in modelling technique. In contrast to the surface docking method the solvent is integrated into the crystalline lattice during modelling procedure. After minimizing its position inside the structure, a classical attachment energy calculation is carried out to determine the binding energies of solvent on the most important faces. Based on the binding energy differences, a modified attachment energy can be computed to get a visible result for the habit influenced by the solvent. For succinic acid the build-in method calculated the habit in the presence of the solvents quite good. In both cases the most important face is predicted correctly. Pure succinic acids most important face is {0 2 0}, in the presence of water it changes to {1 0 0} and with acetonitrile it remains face {0 2 0}. When running the entire modelling procedure for three different water positions inside the structure three different habits were also predicted. Those habits were observed in experiment too. But, the experimental habits grown in aqueous solution suit mostly to those predicted habits where the water molecules did not reach the minimal minimum energy. (C) 2011 Elsevier Ltd. All rights reserved.