ReaxFF/AMBER-A Framework for Hybrid Reactive/Nonreactive Force Field Molecular Dynamics Simulations

Area of Science:

• Computational Chemistry
• Molecular Dynamics

Background:

• Quantum mechanical/molecular mechanical (QM/MM) methods provide insights but are limited by short time scales.
• Reactive force fields offer an intermediate approach to bridge the time-scale gap.

Purpose of the Study:

• To introduce a hybrid ReaxFF/AMBER molecular dynamics tool.
• To enable the study of local reactive events in large systems efficiently.

Main Methods:

• Implementation of ReaxFF reactive force field within the AMBER molecular dynamics software.
• Validation using a benzene molecule in water and comparison with other methods.
• Application to a Claisen rearrangement study using potential of mean force (PMF).

Main Results:

• The ReaxFF/AMBER tool successfully captures bond breaking and formation.
• The hybrid approach is computationally less expensive than QM/MM methods.
• First-time application of PMF studies for organic reactions using ReaxFF.

Conclusions:

• The ReaxFF/AMBER tool provides a powerful and efficient method for studying reactive events in large systems.
• This approach expands the scope of problems addressable in both chemical and biological processes.
• Facilitates the study of complex reactions previously limited by computational cost.