Development of a Charge-Implicit ReaxFF Potential for Hydrocarbon Systems

Area of Science:

• Computational chemistry
• Materials science
• Chemical physics

Background:

• Molecular dynamics (MD) simulations are crucial for understanding chemical and physical processes.
• Developing accurate and efficient interaction potentials is essential for advancing MD simulations.
• Existing ReaxFF potentials face challenges with computational cost and accuracy.

Purpose of the Study:

• To propose a modified ReaxFF potential for carbon and hydrogen systems.
• To enhance computational efficiency and accuracy in MD simulations.
• To address limitations of current charge equilibration methods.

Main Methods:

• Developed a charge-implicit ReaxFF potential, eliminating time-consuming charge equilibration.
• Incorporated an expanded training set for condensed phases.
• Added a repulsive wall for energetic particle bombardment simulations.
• Ensured compatibility with the LAMMPS code.

Main Results:

• The new charge-implicit ReaxFF potential is five times faster than the conventional ReaxFF.
• Achieved significant speedup in simulations of keV particle bombardment on large systems (>800,000 atoms).
• Eliminated flaws associated with the electronegativity equalization method.

Conclusions:

• The charge-implicit ReaxFF potential offers a computationally efficient and accurate alternative for MD simulations.
• This advancement facilitates the study of complex chemical systems and energetic particle interactions.
• The modified potential enhances the applicability of ReaxFF in materials science and chemical physics research.