This application simulates a model of reaction and diffusion on a specialized Erbium lattice, which consists of an fcc lattice for the Erbium and additional tetrahedral and octahedral interstitial sites.
This application stores 2 integers per lattice site. The first integer (i1) is the "type" of the site:
The second integer (i2) is the element on the site:
The 3-fold lattice should be created using the lattice fcc/octa/tetra command, which gives details of its geometry and neighbor connectivity.
The 3-fold lattice should normally be initialized in the following way, using the set command. All fcc sites are for erbium atoms and are fully occupied. All octahedral sites are initially vacant. A fraction of the tetrahedral sites is initialized with hydrogen atoms; the remainder are vacant.
The event command is used to define what kinds of diffusive hops and reaction events occur in the model. These can include correlated hops where a central site coordinates a change at two of its neighbor sites. Reaction events that transmute a Hydrogen atom to a Helium are also possible.
As explained on this page, this application can be evolved only by a kinetic Monte Carlo (KMC). You must thus define a KMC solver to be used with the application via the solve_style command.
For solution by a KMC algorithm, the list of events that can occur at each site is determined by its current neighbors and by the events specified via the event command. The relative probability of each event occurring is computed as a function of the rate or energy value specified in the event command and the temperature specified via the temperature command. The details are explained in the doc page for the event command.
The following additional commands are defined by this application.