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Coarse-graining in interaction space: an analytical approximation for the effective short-ranged electrostatics.
Qiang Shi1, Pu Liu, Gregory A Voth
1Center for Biophysical Modeling and Simulation, Department of Chemistry, University of Utah, 315 S. 1400 E. Rm. 2020, Salt Lake City, Utah 84112-0850, USA.
The Journal of Physical Chemistry. B
|April 16, 2009
Summary
This study analytically investigates effective short-ranged potentials derived from long-ranged electrostatic interactions using force-matching (FM). Findings show forces approach zero at the cutoff and offer an approximation for FM forces in liquid water simulations.
Area of Science:
- Computational chemistry
- Statistical mechanics
- Physical chemistry
Background:
- Long-ranged electrostatic interactions pose challenges in condensed phase simulations.
- The force-matching (FM) method, or coarse-graining in interaction space, offers a way to map these interactions into effective short-ranged potentials.
- Understanding the behavior of these effective potentials is crucial for accurate molecular simulations.
Purpose of the Study:
- To analytically investigate the asymptotic behavior of effective short-ranged potentials derived using the FM method.
- To develop an analytical approximation for the FM short-ranged force.
- To numerically validate the proposed approximation for liquid water systems.
Main Methods:
- Theoretical analysis using the framework of force-matching (FM) theory.
- Asymptotic analysis of effective forces at the FM cutoff radius.
- Numerical testing and validation of the derived analytical approximation.
Main Results:
- Demonstrated that effective forces naturally approach zero at the FM cutoff radius under specific conditions.
- Showed that the difference between the effective FM force and the Coulomb force is approximately linear at shorter distances.
- Developed and numerically validated an analytical approximation for the FM short-ranged force.
Conclusions:
- The developed analytical approximation provides a more accurate representation of FM short-ranged forces.
- This work contributes to the rigorous development of coarse-grained models for electrostatic interactions.
- The findings are directly applicable to improving the efficiency and accuracy of molecular dynamics simulations, particularly for systems like liquid water.
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