General Equilibration of Macromolecular Systems by Kuhn-Scale Mapping and Dynamic Backmapping

Area of Science:

• Computational chemistry
• Polymer science
• Materials science

Background:

• Polymer system equilibration is crucial but challenging due to long relaxation times.
• Atomistic molecular dynamics simulations are often limited by accessible timescales.
• Coarse-grained models require significant effort for chemistry-specific development.

Purpose of the Study:

• To present a novel method, GAMERS, for efficient polymer system equilibration.
• To bypass the need for developing chemistry-specific coarse-grained models.
• To enable accurate polymer simulations with reduced computational resources.

Main Methods:

• GAMERS utilizes phenomenological models and polymer-physics isomorphism for system-specific mapping.
• Time-dependent biasing forces guide atomistic segments to target positions.
• Kremer-Grest models were employed to demonstrate equilibration for four distinct polymers.

Main Results:

• GAMERS rapidly achieved correct polymer densities and chain statistics.
• The method reproduced expected polymer behavior at and above the Kuhn length.
• Initialization strategies significantly impacted mechanical properties, highlighting equilibration importance.

Conclusions:

• GAMERS provides an effective and resource-efficient approach for polymer equilibration.
• The method avoids complex coarse-grained model development.
• GAMERS preserves the advantages of hierarchical equilibration for polymer simulations.