SAPT is a collection of computer codes designed to implement the many-body (body = electron) version of Symmetry-Adapted Perturbation Theory for intermolecular interactions. This code has been extensively used in studies of intermolecular forces. For a description of SAPT see: B. Jeziorski, R. Moszynski, and K. Szalewicz “Perturbation Theory Approach to Intermolecular Potential Energy Surfaces of van der Waals Complexes”, Chem. Rev. 94, 1887-1930 (1994).