title: Performance of extended Lagrangian schemes for molecular dynamics simulations with classical polarizable force fields and density functional theory.
abstract: Iterative energy minimization with the aim of achieving self-consistency is a common feature of Born-Oppenheimer molecular dynamics (BOMD) and classical molecular dynamics with polarizable force fields. In the former, the electronic degrees of freedom are optimized, while the latter often involves an iterative determination of induced point dipoles. The computational effort of the self-consistency procedure can be reduced by re-using converged solutions from previous time steps. However, this must be done carefully, as not to break time-reversal symmetry, which negatively impacts energy conservation. Self-consistent schemes based on the extended Lagrangian formalism, where the initial guesses for the optimized quantities are treated as auxiliary degrees of freedom, constitute one elegant solution. We report on the performance of two integration schemes with the same underlying extended Lagrangian structure, which we both employ in two radically distinct regimes-in classical molecular dynamics simulations with the AMOEBA polarizable force field and in BOMD simulations with the Onetep linear-scaling density functional theory (LS-DFT) approach. Both integration schemes are found to offer significant improvements over the standard (unpropagated) molecular dynamics formulation in both the classical and LS-DFT regimes.
authors.affiliation: School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Valerio
authors.initials: V
authors.lastname: Vitale
authors.affiliation: School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Jacek
authors.initials: J
authors.lastname: Dziedzic
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Albaugh
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Anders M N
authors.identifier: 0000000318564982
authors.initials: AM
authors.lastname: Niklasson
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: Teresa
authors.initials: T
authors.lastname: Head-Gordon
authors.affiliation: School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Chris-Kriton
authors.initials: CK
authors.lastname: Skylaris