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Evaluating the transferability of coarse-grained, density-dependent implicit solvent models to mixtures and chains
Erik C Allen1, Gregory C Rutledge
1Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 USA.
The Journal of Chemical Physics
|January 29, 2009
Summary
Density-dependent implicit solvent (DDIS) potentials accurately predict solvent behavior in mixtures and chains. These potentials, derived from pure solute simulations, show good transferability for radial distribution functions and excess chemical potential in various systems.
Area of Science:
- Computational chemistry
- Statistical mechanics
- Physical chemistry
Background:
- Coarse-graining methods are essential for simulating complex molecular systems.
- Implicit solvent models simplify simulations by representing the solvent as a continuous medium.
- Density-dependent implicit solvent (DDIS) potentials offer a way to capture solvent effects more accurately.
Purpose of the Study:
- To evaluate the transferability of previously developed DDIS potentials.
- To assess the predictive capability of DDIS potentials in systems beyond simple monomeric solutions.
- To determine the accuracy of DDIS potentials for mixtures, solute chains, and mixed-composition chains.
Main Methods:
- Utilized coarse-graining to develop local density-dependent implicit solvent (DDIS) potentials.
- Simulated monomeric solute in monomeric solvent to derive initial DDIS potentials.
- Tested the transferability of these potentials to systems with mixtures of solutes and solute chains.
- Analyzed the radial distribution function (RDF) and solute excess chemical potential for accuracy.
Main Results:
- DDIS potentials demonstrated very good transferability for RDF in mixtures.
- RDF errors increased linearly with chain length for systems containing solute chains.
- Excess chemical potential transferability was good for mixtures at low concentrations, chains, and mixed-composition chains.
- Chemical potential transferability failed at higher concentrations in mixtures due to the DDIS potential's nature.
Conclusions:
- DDIS potentials derived for pure solutes exhibit significant transferability to more complex systems.
- These potentials are effective for studying mixtures, chains, and mixed-composition chains in monomeric solvents.
- The findings support the broader applicability of DDIS potentials in computational chemistry.
- Limitations in chemical potential transferability at high concentrations were identified.
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