title: Frequency-dependent force fields for QMMM calculations.
abstract: We outline the construction of frequency-dependent polarizable force fields. The force fields are derived from analytic response theory for different frequencies using a generalization of the LoProp algorithm giving a decomposition of a molecular dynamical polarizability to localized atomic dynamical polarizabilities. These force fields can enter in a variety of applications - we focus on two such applications in this work: firstly, they can be incorporated in a physical, straightforward, way for current existing methods that use polarizable embeddings, and we can show, for the first time, the effect of the frequency dispersion within the classical environment of a quantum mechanics-molecular mechanics (QMMM) method. Our methodology is here evaluated for some test cases comprising water clusters and organic residues. Secondly, together with a modified Silberstein-Applequist procedure for interacting inducible point-dipoles, these frequency-dependent polarizable force fields can be used for a classical determination of frequency-dependent cluster polarizabilities. We evaluate this methodology by comparing with the corresponding results obtained from quantum mechanics or QMMM where the absolute mean [small alpha, Greek, macron] is determined with respect to the size of the QM and MM parts of the total system.
authors.affiliation: KTH Royal Institute of Technology, School of Biotechnology, Division of Theoretical Chemistry and Biology, SE-106 91 Stockholm, Sweden. harczuk@kth.se.
authors.forename: Ignat
authors.initials: I
authors.lastname: Harczuk
authors.forename: Olav
authors.initials: O
authors.lastname: Vahtras
authors.forename: Hans
authors.initials: H
authors.lastname: Ågren
mesh_terms: D056004:Molecular Dynamics Simulation; D011789:Quantum Theory; D013696:Temperature; D014364:Tryptophan / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D014364:Tryptophan