title: Feature activated molecular dynamics: an efficient approach for atomistic simulation of solid-state aggregation phenomena.
abstract: An efficient approach is presented for performing efficient molecular dynamics simulations of solute aggregation in crystalline solids. The method dynamically divides the total simulation space into "active" regions centered about each minority species, in which regular molecular dynamics is performed. The number, size, and shape of these regions is updated periodically based on the distribution of solute atoms within the overall simulation cell. The remainder of the system is essentially static except for periodic rescaling of the entire simulation cell in order to balance the pressure between the isolated molecular dynamics regions. The method is shown to be accurate and robust for the Environment-Dependant Interatomic Potential (EDIP) for silicon and an Embedded Atom Method potential (EAM) for copper. Several tests are performed beginning with the diffusion of a single vacancy all the way to large-scale simulations of vacancy clustering. In both material systems, the predicted evolutions agree closely with the results of standard molecular dynamics simulations. Computationally, the method is demonstrated to scale almost linearly with the concentration of solute atoms, but is essentially independent of the total system size. This scaling behavior allows for the full dynamical simulation of aggregation under conditions that are more experimentally realizable than would be possible with standard molecular dynamics.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6393, USA.
authors.forename: Manish
authors.initials: M
authors.lastname: Prasad
authors.forename: Talid
authors.initials: T
authors.lastname: Sinno
mesh_terms: D002627:Chemistry, Physical / Q000379:methods*; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry; D003460:Crystallization; D004058:Diffusion; D019281:Dimerization; D006358:Hot Temperature; D015233:Models, Statistical; D008968:Molecular Conformation; D015394:Molecular Structure; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry; D013696:Temperature
chemical_list: D003300:Copper; D012825:Silicon