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Monday, June 09, 2014
10:00 AM - 11:00 AM
CNLS Conference Room (TA-3, Bldg 1690)

Postdoc Seminar

Rigorous Methods to Bias Molecular Simulations with Experimental Data

Andrew White
University of Chicago

A primary goal in molecular simulations is to modify the potential energy of a system so that properties of the simulation match known experimental data. This is traditionally done through iterative cycles of simulation and re-parameterization. An alternative approach is to add terms to bias the potential energy so the system matches experimental data directly. This can be done while minimally changing the underlying free energy of the molecular simulation. I'll present two methods, one for when expected values are to be match and one when complete probability distributions are to be matched. The first method, called experiment directed simulation, converges rapidly, can match many data simultaneously, and minimally modifies the potential (maintains maximum entropy). The method has been tested on model systems and a three-component electrolyte simulation. Experiment directed simulations can only match expected values in molecular simulations. I'll also present a second method call targeted metadynamics, which can be used when a complete probability distribution of arbitrary collective variables is known and we wish to modify the potential energy surface to match it. These two new methods open new ways to directly combine simulations and experiments.

Host: Gregory A. Voth