SYMMETRY-ADAPTED PERTURBATION-THEORY CALCULATIONS OF URACIL WATER INTERACTION ENERGY

Interaction energies for the uracil-water system at two configurations close to the van der Waals minimum were computed using many-body symmetry-adapted perturbation theory of intermolecular interactions at the level which includes major electron correlation effects. Supermolecular interaction energies at the second-order many-body perturbation theory level were computed as well. A minimal isotropic plus single polarization basis set was used. The results show that correlation effects are responsible for about 20% of the interaction energy. These effects exhibit a strong dependence on the geometry of the system. Our work demonstrates that it is now feasible to compute intermolecular interaction energies for systems of biochemical interest including a reliable treatment of the electron correlation effects.