title: Revisiting the Exact Relation between Potential of Mean Force and Free-Energy Profile.
abstract: Constraints are convenient in the calculation of free energy profiles via molecular dynamics simulations, but they subtly alter the phase space distribution. In a recent letter of a related title in this journal, Wong and York [J. Chem. Theory Comput. 2012, 8, 3998-4003] suggest replacing Fixman's mass-metric correction with its inverse and adding a Jacobian contribution to the potential of mean constraint force. This letter refutes both suggestions, discusses the underlying interpretation problems, and provides supporting numerical simulations.
authors.affiliation: Multi Scale Mechanics, Faculty of Engineering Technology, and Computational BioPhysics, Faculty of Science and Technology, and MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Wouter K
authors.initials: WK
authors.lastname: den Otter