title: Artificial Bee Colony Optimization of Capping Potentials for Hybrid Quantum Mechanical/Molecular Mechanical Calculations.
abstract: We present an algorithmic extension of a numerical optimization scheme for analytic capping potentials for use in mixed quantum-classical (quantum mechanical/molecular mechanical, QM/MM) ab initio calculations. Our goal is to minimize bond-cleavage-induced perturbations in the electronic structure, measured by means of a suitable penalty functional. The optimization algorithm-a variant of the artificial bee colony (ABC) algorithm, which relies on swarm intelligence-couples deterministic (downhill gradient) and stochastic elements to avoid local minimum trapping. The ABC algorithm outperforms the conventional downhill gradient approach, if the penalty hypersurface exhibits wiggles that prevent a straight minimization pathway. We characterize the optimized capping potentials by computing NMR chemical shifts. This approach will increase the accuracy of QM/MM calculations of complex biomolecules.
authors.affiliation: Physics Department, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schiffmann
authors.affiliation: Physics Department, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sebastiani