Predicting lattice energy of organic crystals by density functional theory with empirically corrected dispersion energy

Calculation of the lattice energy of organic crystals is needed for predicting important structural and physicochemical properties such as polymorphism and growth morphology. Quantum mechanical methods that can be used for calculating typical organic crystals are unable to fully estimate van der Waals energies in a crystal. A method by augmenting the density functional theory with an analytical, nonelectronic approach for accounting for the dispersion energy was tested for selected organic crystals. The results illustrate the feasibility of this method for the prediction of the lattice energy of organic crystals. It is also shown that the dispersion energy is a dominant component of the lattice energy, particularly for those organic crystals that have no hydrogen bonds.