title: Semiempirical Quantum-Chemical Orthogonalization-Corrected Methods: Theory, Implementation, and Parameters.
abstract: Semiempirical orthogonalization-corrected methods (OM1, OM2, and OM3) go beyond the standard MNDO model by explicitly including additional interactions into the Fock matrix in an approximate manner (Pauli repulsion, penetration effects, and core-valence interactions), which yields systematic improvements both for ground-state and excited-state properties. In this Article, we describe the underlying theoretical formalism of the OMx methods and their implementation in full detail, and we report all relevant OMx parameters for hydrogen, carbon, nitrogen, oxygen, and fluorine. For a standard set of mostly organic molecules commonly used in semiempirical method development, the OMx results are found to be superior to those from standard MNDO-type methods. Parametrized Grimme-type dispersion corrections can be added to OM2 and OM3 energies to provide a realistic treatment of noncovalent interaction energies, as demonstrated for the complexes in the S22 and S66×8 test sets.
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Pavlo O
authors.initials: PO
authors.lastname: Dral
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Xin
authors.initials: X
authors.lastname: Wu
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Lasse
authors.initials: L
authors.lastname: Spörkel
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Koslowski
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Weber
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Steiger
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Scholten
authors.affiliation: Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Thiel