title: AM1* parameters for phosphorus, sulfur and chlorine.
abstract: An extension of the AM1 semiempirical molecular orbital technique, AM1*, is introduced. AM1* uses AM1 parameters and theory unchanged for the elements H, C, N, O and F. The elements P, S and Cl have been reparameterized using an additional set of d orbitals in the basis set and with two-center core-core parameters, rather than the Gaussian functions used to modify the core-core potential in AM1. Voityuk and Rösch's AM1(d) parameters have been adopted unchanged for AM1* with the exception that new core-core parameters are defined for Mo-P, Mo-S and Mo-Cl interactions. Thus, AM1* gives identical results to AM1 for compounds with only H, C, N, O, and F, AM1(d) for compounds containing Mo, H, C, N, O and F only, but differs for molybdenum compounds containing P, S or Cl. The performance and typical errors of AM1* are discussed.
authors.affiliation: Computer-Chemie-Centrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nägelsbachstrasse 25, 91052 Erlangen, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Winget
authors.forename: Anselm H C
authors.initials: AH
authors.lastname: Horn
authors.forename: Cenk
authors.initials: C
authors.lastname: Selçuki
authors.forename: Bodo
authors.initials: B
authors.lastname: Martin
authors.forename: Timothy
authors.initials: T
authors.lastname: Clark
mesh_terms: D002713:Chlorine / Q000737:chemistry*; D008962:Models, Theoretical; D008968:Molecular Conformation; D010758:Phosphorus / Q000737:chemistry*; D011789:Quantum Theory; D013455:Sulfur / Q000737:chemistry*
chemical_list: D010758:Phosphorus; D002713:Chlorine; D013455:Sulfur