  An investigation to optimize the application of the third-generation charge
optimized many-body (COMB3) interatomic potential and associated input
parameters was carried out through the study of solid-liquid interactions in
classical molecular dynamics (MD) simulations. The rates of these molecular
interactions are understood though the wetting rates of water nano droplets on
a bare copper (111) surface. Implementing the Langevin thermostat, the
influence of simulation time step, the number of atoms in the system, the
frequency at which charge equilibration is performed, and the temperature
relaxation rate are all examined. The results indicate that time steps of 0.4
fs are possible when using longer relaxation times for the system temperature,
which is almost double the typical time step used for reactive potentials. The
use of the QEq charge equilibration allows for a fewer atomic layers to be used
in the Cu slab. In addition, charge equilibrium schemes do not need to be
performed every time step to ensure accurate charge transfer. Interestingly,
the rate of wetting for the nanodroplets is dominantly dependent on the
temperature relaxation time which are predicted to significantly change the
viscosity of the water droplets. This work provides a pathway for optimizing
simulations using the COMB3 reactive interatomic potential.
