"""Lennard jones 6 -12 translational potential."""
from numpy import einsum, add, subtract, zeros
__all__ = ['vv_trans', 'ff_trans']
[docs]def vv_trans(self):
"""Lennard Jones Potential."""
# unit: erg
self.lj6[:] = (self.sigma * self.rij)**6
self.epot_tr[:] = 4. * self.epsilon * self.lj6 * (self.lj6 - 1.)
[docs]def ff_trans(self):
"""Calculate Translational Force."""
self.force_trans[:] = 0
self.lj6[:] = (self.sigma * self.rij) ** 6
einsum("i, ij, i-> ij",
self.epsilon24 * (2. * self.lj6 - 1.) * self.lj6,
self.rijz, self.rij * self.rij, out=self.ftrans)
subtract.at(self.force_trans, self.ia, self.ftrans)
add.at(self.force_trans, self.ja, self.ftrans)
def setup():
import mango.position as mp
mp.c.Error("M Lennard Jones potential run")
setup()