title: A comparison between QM/MM and QM/QM based fitting of condensed-phase atomic polarizabilities.
abstract: Recently we reported a combined QM/MM approach to estimate condensed-phase values of atomic polarizabilities for use in (bio)molecular simulation. The setup relies on a MM treatment of the solvent when determining atomic polarizabilities to describe the response of a QM described solute to its external electric field. In this work, we study the effect of using alternative descriptions of the solvent molecules when evaluating atomic polarizabilities of a methanol solute. In a first step, we show that solute polarizabilities are not significantly affected upon substantially increasing the MM dipole moments towards values that are typically reported in literature for water solvent molecules. Subsequently, solute polarization is evaluated in the presence of a QM described solvent (using the frozen-density embedding method). In the latter case, lower oxygen polarizabilities were obtained than when using MM point charges to describe the solvent, due to introduction of Pauli-repulsion effects.
authors.affiliation: AIMMS Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, the Netherlands. d.p.geerke@vu.nl.
authors.forename: C Ruben
authors.initials: CR
authors.lastname: Vosmeer
authors.forename: Karin
authors.initials: K
authors.lastname: Kiewisch
authors.forename: Karlijn
authors.initials: K
authors.lastname: Keijzer
authors.forename: Lucas
authors.initials: L
authors.lastname: Visscher
authors.forename: Daan P
authors.initials: DP
authors.lastname: Geerke