GroLigFF 2.0: GROMOS force field compatible parameters for Heteromolecules

A web-server to generate GROMOS (force field)-compatible parameters for large organic drug-like molecules, complex natural products, macromolecules and polymers is presented. The web-server GroLigFF (https://groligff.net) provides force field topology and parameters that can be used to perform Molecular Dynamics (MD) simulations, Linear Interaction Energy (LIE) calculations and Alchemical Free Energy (FE) calculations. The force field description is generated combining the GROMOS 54A7 biomolecular force field for bonded and van der Waals parameters with a Bond Charge Increment (BCI) Model for partial atomic charges. The output parameters can be used with Gromos, Gromacs and Amber (with gromos2amber conversion) programs with a recommended single range 1.4 nm cut-off for non-bonded interactions. In addition, the “BCI atomic charges” can be extracted from the output MOL2 file and can be used an alternate charge model for OPLS, GAFF, CHARMM and OpenFF force field topologies for heteromolecules, additional validation may be required.