[gmx-users] How possible applying two different force field parameters for two-component in Gromacs simulation

[mohammad torabi]

Dear users of Gromacs,
I am starting with Gromacs for a short time. I want to prepare a simulation system including 2 components (Protein + ionic liquid) but their available force fields have different sources (OPLS-AA existing in Gromacs data bank and a specific FF based on Lopes & Padua IL force field outside the Gromacs data bank). How can I properly use (mix) these 2 different force fields for my system components in the topology file of Gromacs code.
Best Regards,S. M. Torabi