41 lines
1.3 KiB
Python
Executable File
41 lines
1.3 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 BondTabulate
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################################################################################
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import math
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def morse_energy(r):
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depth = 1.0
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width = 2.0
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rzero = 1.2
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ralpha = math.exp(-width*(r-rzero))
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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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depth = 1.0
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width = 2.0
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rzero = 1.2
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ralpha = math.exp(-width*(r-rzero))
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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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btable = BondTabulate(morse_energy, morse_force, units='lj')
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btable.run('MORSE')
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