Hamiltonian replica-exchange method α-REMD for ring spearing elimination in polymers

Area of Science:

• Polymer Science
• Computational Chemistry
• Materials Science

Background:

• Accurate molecular dynamics (MD) simulations require well-relaxed polymer structures.
• De-novo polymer models often contain structural defects like close contacts and ring spearing.
• Existing methods struggle to eliminate ring spearing and achieve complete relaxation.

Purpose of the Study:

• To develop a robust method for eliminating structural defects in polymer models.
• To improve the accuracy of polymer property predictions using MD simulations.
• To address the challenge of ring spearing in ring-containing polymers.

Main Methods:

• Development of alpha-Replica Exchange MD (α-REMD), a Hamiltonian replica-exchange protocol.
• Application of α-REMD to five polyethersulfone models with initial structural defects.
• Validation of defect elimination and structure relaxation through simulation.

Main Results:

• α-REMD successfully eliminated all ring spearing defects in the tested polyethersulfone models.
• The protocol achieved general structure relaxation, improving model quality.
• Demonstrated efficiency of α-REMD in preparing polymer structures for MD simulations.

Conclusions:

• α-REMD is an effective protocol for defect removal and structure relaxation in polymer modeling.
• This method enhances the reliability of polymer property predictions via MD simulations.
• α-REMD offers a significant advancement for simulating complex polymer systems, especially those with rings.