Polarization and basis set superposition error in interaction energies in the fragment molecular orbital method

By separating polarization contributions from interaction energies, a clear picture of binding is obtained for the fragment molecular orbital method (FMO). A scheme for incorporating basis set superposition error (BSSE) corrections in solution is proposed for FMO, featuring a coupling of BSSE-induced charge transfer and the embedding potential due to solvent. The developed method is applied to a water cluster and a prion polypeptide-ligand complex (PDB: 4TUT).