Coarse-grained conformational surface hopping: Methodology and transferability

Area of Science:

• Computational Chemistry
• Molecular Dynamics
• Statistical Mechanics

Background:

• Traditional molecular dynamics (MD) is computationally expensive.
• Coarse-graining (CG) reduces complexity but often sacrifices accuracy.
• Multisurface dynamics offers a framework for improved accuracy in complex systems.

Purpose of the Study:

• To detail and extend the Coarse-Grained Conformational Surface Hopping (CG SH) methodology.
• To assess the impact of CG SH on liquid properties, including non-bonded interactions.
• To investigate the transferability of CG SH force fields across different systems and thermodynamic conditions.

Main Methods:

• Adaptation of multisurface dynamics for classical molecular dynamics.
• Coupling distinct conformational basins (states) using unique force fields (surfaces).
• Application to toy and three-bead hexane models, and extension to non-bonded interactions.

Main Results:

• CG SH significantly improves the approximation of the many-body potential of mean force.
• The methodology accurately reproduces liquid properties.
• Demonstrated good agreement with atomistic calculations for temperature and composition variations.

Conclusions:

• CG SH provides a more accurate classical molecular dynamics description at a reduced level.
• The study introduces a "weak-transferability regime" for CG force fields.
• CG SH offers a promising approach for efficient and transferable molecular simulations.