[Chimera-users] Molecular dynamics

Good day! My name is Sergei Vladimirov, I'm a student at Moscow State University. As far as I know, when running a molecular dynamics of ligand-protein interaction one must use different force fields to the ligand and the protein. There is a mm14ff to calculate interactions within a protein but there are only two different force fields to calculate interactions within a ligand. I've been led into believing that the best ff for small organic ligands is GAFF. So my question is, is there any way to implement the GAFF force field into the production of molecular dynamics? Is there anything I'm missing? I will be awaiting your reply. Best regards, Sergei Vladimirov.