The solvent has a large effect on the crystal morphology of the organic explosive compound RDX. Molecular dynamics simulations of a solvent layer of gamma -butyrolactone upon {200} and {210} RDX crystal surfaces were performed to obtain a more profound understanding of the behaviour of these solvent molecules near a crystal surface. The average potential energy of the solvent molecules near the surfaces was found to be higher than in the solvent bulk. This surface induced potential energy change might be an adequate solvent effect parameter to use in a prediction of the morphological importance of a crystal surface. From the calculated surface induced potential energy changes it follows that the {210} face is morphologically more important than the {200} surface. This agrees well with the observed experimental RDX morphology grown from the solvent gamma -butyrolactone where the {210} face is large and the {200} is not visible at all.