Optimization approach in variable-charge potential for metal/metal oxide systems

Earlier attempts on minimizing the total system energy of metal/metal oxide systems with given charge constraints appear to be indirect and unnecessarily complicated. The energy minimization problem is in fact a constrained optimization problem and hence can be solved by a constrained optimization method. We propose a new direct approach for finding charge distributions among ions in molecular dynamics simulations. The approach is based on an optimization algorithm, called the Generalized Reduced Gradient (GRG) Method. This efficient approach can be readily employed in molecular dynamic simulations for metal/metal oxide systems.