Dimorphic forms of 4-(4-hydroxypiperidinyl)nitrobenzene which are second harmonic generation (SHG) active and inactive are investigated. Crystallization from a variety of solvents clearly demonstrate the preferential formation of the centrosymmetric structure in polar solvents and the noncentrosymmetric structure in nonpolar solvents. Semiempirical quantum chemical calculations including solvation effects on supramolecular fragments of the crystals reveal the solvent selection of the crystalline forms. The potential of this approach to address the general problem of polymorphism in molecular materials is indicated.