forked from lijiext/lammps
34 lines
1.4 KiB
Plaintext
34 lines
1.4 KiB
Plaintext
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This directory has an input script that illustrates how to use LAMMPS
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as an energy-evaluation engine in a Monte Carlo (MC) relaxation loop.
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It is just an illustration of how to do this for a toy 2d problem, but
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the script is fairly sophisticated in its use of variables, looping,
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and an if-the-else statement which applies the Boltzmann factor to
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accept or reject a trial atomic-displacement move.
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The script sets up a perfect 2d hex lattice, then perturbs all
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the atom positions to "disorder" the system. It then
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loops in the following manner:
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pick a random atom and displace it to a random new position
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evaluate the change in energy of the system due to
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the single-atom displacement
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accept or reject the trial move
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if accepted, continue to the next iteration
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if rejected, restore the atom to its original position
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before continuing to the next iteration
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The 6 variables at the top of the input script can be adjusted
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to play with various MC parameters.
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When the script is finished, statistics about the MC procedure
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are printed.
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Dump file snapshots or images or a movie of the MC relaxation can be
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produced by uncommenting the appropriate dump lines in the script.
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At some point, we will add a Python script to the python/examples
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directory that performs the same operation as this script. It will
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invoke LAMMPS as a library and use Python to implement the MC
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accept/reject logic more cleanly than the LAMMPS input script can do
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it.
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