Model interaction potentials

The TransRot project is compatible with a range of pairwise additive model potentials, and some of them are described here. Of course, our implementation is limited to rigid-body assumptions.

1. We have made extensive use of the Jorgensen groups' OPLS-AA, OPLS-UA (1997), and TIP3P/TIP4P/TIP5P models for project work, which are implemented in their powerful BOSS Monte Carlo simulation software, as well as within the Tinker project, a powerful suite for molecular modeling. See here: (https://jorgensenresearch.com/software) and here: https://dasher.wustl.edu/tinker/ . Our default combination rules use geometric means for $C_{ij}$ and $D_{ij}$, which are consistent with these force fields, and so atom type parameters from these models can be used directly.

2. The TraPPE force field from the Siepmann group does not use the same combination rules as TransRot; TraPPE uses the Lorentz-Berthelot combination rules, whereas TransRot defaults to the use of geometric means. However, TransRot's default combination rules can be easily overridden and the correct pair interactions provided explicitly. The TraPPE parameters and correct rules for a number of molecules can be obtained here: (http://trappe.oit.umn.edu/#param_content)