Predicting structure of molecular crystals from first principles.

A recently developed method, symmetry-adapted perturbation theory based on the density-functional description of monomers [SAPT(DFT)], is shown to be sufficiently accurate and numerically efficient to facilitate predictions of the structure of molecular crystals from first principles. In one application, a SAPT(DFT) potential was used to generate and order polymorphs of the cyclotrimethylene trinitramine crystal, resulting in the lowest-energy structure in excellent agreement with the experimental crystal. In a different application, a SAPT(DFT)-based calculation reproduced the lattice energy of the benzene crystal to within a few percent.