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what

THE COMPUTATIONAL PHYSICS of ATOMISTIC SIMULATIONS

  • Two general approaches - Molecular Dynamics and Simulated Annealing.

  • MOLECULAR DYNAMICS - Solve Newton's equations with appropriate potentials. Mimic all experimental process such as heating, cooling, applying pressure. REAL dynamics, real processes. Finite temperatures much harder than T=0. Deterministic, although at finite temperatures randomness in selection of initial thermalization.

    SEE here for ``Cats and Apples''

  • SIMULATED ANNEALING - Find equilibrium states efficiently and reliably. Does not follow true developments in time. Easier to do at finite temperatures. Stochastic, working within ensemble.

  • Best to be able to use both algorithms as appropriate; both use same potentials!

  • Also need to keep in mind Statistical Mechanics models such as PERCOLATION!!