77 lines
2.2 KiB
Python
Executable File
77 lines
2.2 KiB
Python
Executable File
#!/usr/bin/env python
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# ----------------------------------------------------------------------
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# LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
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# https://www.lammps.org/ Sandia National Laboratories
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# LAMMPS Development team: developers@lammps.org
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#
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# Copyright (2003) Sandia Corporation. Under the terms of Contract
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# DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
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# certain rights in this software. This software is distributed under
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# the GNU General Public License.
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#
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# See the README file in the top-level LAMMPS directory.
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# -------------------------------------------------------------------------
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from tabulate import WallTabulate
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import os, sys
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################################################################################
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import math
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k = 100.0
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rzero = 4.0
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epsilon = 0.02
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sigma = 2.0
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depth = 20.0
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width = 2.0
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r0 = 1.2
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def harmonic_force(r):
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dr = r - rzero
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f = -2.0 * k * dr
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return f
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def harmonic_energy(r):
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dr = r - rzero
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f = k * dr * dr
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return f
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def lj126_force(r):
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f = -4.0*epsilon*(-12.0*math.pow(sigma/r,12.0)/r + 6.0*math.pow(sigma/r,6.0)/r)
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return f
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def lj126_energy(r):
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f = 4.0*epsilon*(math.pow(sigma/r,12.0) - math.pow(sigma/r,6.0))
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return f
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def morse_energy(r):
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ralpha = math.exp(-width*(r-r0))
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f = depth * (-1.0 + (1.0 - ralpha) * (1.0 - ralpha))
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return f
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def morse_force(r):
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ralpha = math.exp(-width*(r-r0))
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f = -2.0 * depth * width * (1.0 -ralpha) * ralpha
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return f
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################################################################################
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if __name__ == "__main__":
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fname = 'walltab.dat'
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if os.path.exists(fname):
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os.remove(fname)
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sys.argv.append('--filename')
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sys.argv.append(fname)
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sys.argv.append('--num-points')
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sys.argv.append('400')
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sys.argv.append('--inner')
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sys.argv.append('0.01')
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sys.argv.append('--outer')
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sys.argv.append('4.0')
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wtable = WallTabulate(harmonic_energy, harmonic_force, units='real')
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wtable.run('HARMONIC')
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wtable = WallTabulate(lj126_energy, lj126_force, units='real')
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wtable.run('LJ126')
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wtable = WallTabulate(morse_energy, morse_force, units='real')
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wtable.run('MORSE')
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