A module for defining the SPCE forcefield

This definition of the SPCE forcefield includes bond and bond angle strengths as these are needed for to create the required HarmonicPotentials. As a result, they can be used for simulating a flexible water molecule. However, SPCE itself is a rigid model, and in order to replicate this a constraint algorithm should be used for all Bond and BondAngle objects.

Parameters (excluding bond strengths) are from:

The missing term in effective pair potentials H. J. C. Berendsen, J. R. Grigera, and T. P. Straatsma J. Phys. Chem. 1987, 91, 24, 6269–6271

The strengths provided are the same as those used for SPC, from:

A molecular dynamics simulation of a water model with intramolecular degrees of freedom O. Teleman, B. Jonsson, S. Engstrom Mol. Phys. 60(1), 193-203 (1987)

Note that different values for bond strengths are given in the OPLSAA data file, namely 2510.4 and 313.8 respectively.

class MDMC.MD.force_fields.SPCE.SPCE[source]

SPCE force field - LJ, Coulombic, fixed bond lengths and angles

property interaction_dictionary

The dict of interactions that exist within the ForceField


{Interaction:Elements} where Elements is an ordered tuple of elemental symbols, and values of InteractionFunction objects.

Return type