espressopp.interaction.CoulombTruncated

\[U = k\frac{q_iq_j}{d_{ij}}\]

where \(k\) is the user-supplied prefactor, \(q_i\) is the charge of particle i, and \(d_{ij}\) is interparticle distance

In this interaction potential, a different charge can be associated with each particle. For a truncated Coulomb interaction potential where only one \(q_iq_j\) value is specified for all interactions, see CoulombTruncatedUniqueCharge.

espressopp.interaction.CoulombTruncated(prefactor, cutoff)
Parameters:

  • prefactor (real) – (default: 1.0) user-supplied prefactor k

  • cutoff (real) – (default: infinity) user-supplied interaction cutoff

espressopp.interaction.VerletListCoulombTruncated(vl)
Parameters:

vl (espressopp.VerletList) – verlet list object defined earlier in python script

espressopp.interaction.VerletListCoulombTruncated.getPotential(type1, type2)
Parameters:

  • type1 (integer) – type of first atom in pair

  • type2 (integer) – type of second atom in pair

espressopp.interaction.VerletListCoulombTruncated.setPotential(type1, type2, potential)
Parameters:

  • type1 (integer) – type of first atom in pair

  • type2 (integer) – type of second atom in pair

  • potential (CoulombTruncated potential) – potential object defined earlier in python script

espressopp.interaction.FixedPairListTypesCoulombTruncated(system, vl)
Parameters:

  • system (espressopp.System) – system object defined earlier in the python script

  • vl (espressopp.FixedPairList) – fixedpairlist object defined earlier in the python script

espressopp.interaction.FixedPairListTypesCoulombTruncated.setPotential(potential)
Parameters:

  • type1 (integer) – type of first atom in pair

  • type2 (integer) – type of second atom in pair

  • potential (CoulombTruncated potential) – potential object defined earlier in python script

#Example:

>>> pref = 138.935485
>>> rc = 1.2
>>> fixedpairlist = espressopp.FixedPairList(system.storage)
>>> fixedpairlist.addBonds([(1,2),(2,3)])
>>> pot = espressopp.interaction.CoulombTruncated(prefactor=pref, cutoff=rc)
>>> interaction=espressopp.interaction.FixedPairListTypesCoulombTruncated(system,fixedpairlist)
>>> interaction.setPotential(type1=0, type2=1, potential=pot)
>>> system.addInteraction(interaction)
class espressopp.interaction.CoulombTruncated.CoulombTruncated(*args, **kwds)

The CoulombTruncated potential.