Development of a Charge-Implicit ReaxFF Potential for Hydrocarbon Systems

Molecular
dynamics (MD) simulations continue to make important
contributions to understanding chemical and physical processes. Concomitant
with the growth of MD simulations is the need to have interaction
potentials that both represent the chemistry of the system and are
computationally efficient. We propose a modification to the ReaxFF
potential for carbon and hydrogen that eliminates the time-consuming
charge equilibration, eliminates the acknowledged flaws of the electronegativity
equalization method, includes an expanded training set for condensed
phases, has a repulsive wall for simulations of energetic particle
bombardment, and is compatible with the LAMMPS code. This charge-implicit
ReaxFF potential is five times faster than the conventional ReaxFF
potential for a simulation of keV particle bombardment with a sample
size of over 800 000 atoms.