espressopp.interaction.DihedralRB

The proper dihedral with Ryckaert-Bellemans form.

\[U_{rb}(\phi_{ijkl}) = \sum_{n=0}^{5} K_n (cos(\theta))^n\]

where the \(\theta = \phi - 180^\circ\) and \(K_{0\dotso5}\) are the coefficients.

By default the IUPAC convention is used, where \(\phi\) is the angle between planes \(ijk\) and \(jkl\). The \(0^\circ\) corresponds to the cis configuration.

Reference: http://www.gromacs.org/Documentation/Manual

espressopp.interaction.DihedralRB(K0, K1, K2, K3, K4, K5, iupac)
Parameters:

  • K0 (real) – (default: 0.0)

  • K1 (real) – (default: 0.0)

  • K2 (real) – (default: 0.0)

  • K3 (real) – (default: 0.0)

  • K4 (real) – (default: 0.0)

  • K5 (real) – (default: 0.0)

  • iupac – (default: True)

espressopp.interaction.FixedQuadrupleListDihedralRB(system, vl, potential)
Parameters:

  • system

  • vl

  • potential

espressopp.interaction.FixedQuadrupleListDihedralRB.getFixedQuadrupleList()
Return type:

A Python list of lists.

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

  • type1

  • type2

  • potential