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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Density-dependent analysis of nonequilibrium paths improves free energy estimates
1Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-0520, USA. daveminh@gmail.com
The Journal of Chemical Physics
|June 3, 2009
Summary
Analyzing nonequilibrium paths with different protocols can improve free energy estimates. Minimizing lag between nonequilibrium and equilibrium densities enhances accuracy and precision in these calculations.
Area of Science:
- Statistical mechanics
- Physical chemistry
- Computational physics
Background:
- Systems driven out of equilibrium follow nonequilibrium paths.
- Nonequilibrium work theorems use path samples to estimate equilibrium quantities like free energy.
- Analyzing paths with different protocols is a novel approach.
Purpose of the Study:
- To investigate the impact of analysis protocols on free energy estimates.
- To determine if minimizing lag improves accuracy and precision.
- To explore the utility of reprocessed trajectories in nonequilibrium thermodynamics.
Main Methods:
- Simulating systems driven out of equilibrium with time-dependent protocols.
- Analyzing trajectories generated by one protocol using a different analysis protocol.
- Employing minimal lag analysis protocols based on exactly soluble propagators and relative entropies.
Main Results:
- Analysis protocols that minimize lag between nonequilibrium and equilibrium densities reduce dissipation.
- Reprocessed trajectories with minimal lag yield more accurate free energy estimates.
- Substantial gains in accuracy and precision were observed across test cases.
Conclusions:
- Minimizing lag is a key factor for improving free energy estimates from nonequilibrium paths.
- The choice of analysis protocol significantly impacts the reliability of thermodynamic quantity estimations.
- This method offers a promising approach for enhanced free energy calculations in driven systems.
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