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 –