Optimization and application of lithium parameters for the reactive force field, ReaxFF

Area of Science:

• Computational Chemistry
• Materials Science
• Chemical Physics

Background:

• Molecular dynamics (MD) simulations require accurate force fields for simulating complex chemical systems.
• Simulating large-scale reactive systems involving lithium, hydrogen, and carbon presents significant challenges due to complex bonding and reactions.

Purpose of the Study:

• To develop and optimize a reactive force field (ReaxFF) suitable for large-scale molecular dynamics simulations of lithium-hydrogen (Li-H) and lithium-carbon (Li-C) chemical systems.
• To enhance the predictive capabilities of computational methods for materials involving lithium.

Main Methods:

• Optimized ReaxFF parameters by fitting to density functional theory (DFT) calculation results for various Li-H and Li-C molecules.
• Validated the ReaxFF parameters against DFT data for structures and energy barriers of small molecules.
• Tested the accuracy of the developed ReaxFF by comparing with dissociation energies of lithium-benzene compounds and lithium atom collisions with C(60).
• Incorporated equations of state and lattice parameters for condensed phases of lithium into the parameterization process.

Main Results:

• Successfully optimized ReaxFF parameters for Li-H and Li-C systems.
• The developed ReaxFF accurately reproduces DFT-calculated properties for a range of Li-H and Li-C molecules.
• Validation studies confirmed the ReaxFF's reliability in predicting dissociation energies and collision behaviors.

Conclusions:

• The optimized ReaxFF provides a practical tool for large-scale MD simulations of reactive Li-H and Li-C systems.
• This advancement facilitates the study of complex chemical reactions and material properties involving lithium.
• The validated force field opens new avenues for computational materials design and discovery.