title: Mathematical modeling and physical reality in noncovalent interactions.
abstract: The Hellmann-Feynman theorem provides a straightforward interpretation of noncovalent bonding in terms of Coulombic interactions, which encompass polarization (and accordingly include dispersion). Exchange, Pauli repulsion, orbitals, etc., are part of the mathematics of obtaining the system's wave function and subsequently its electronic density. They do not correspond to physical forces. Charge transfer, in the context of noncovalent interactions, is equivalent to polarization. The key point is that mathematical models must not be confused with physical reality.
authors.affiliation: Department of Chemistry, University of New Orleans, New Orleans, LA, 71048, USA, ppolitze@uno.edu.
authors.forename: Peter
authors.initials: P
authors.lastname: Politzer
authors.forename: Jane S
authors.initials: JS
authors.lastname: Murray
authors.forename: Timothy
authors.initials: T
authors.lastname: Clark