All force fields produced reasonable simulations without major artefacts that could be traced back to the parameterization of the force fields. The RNA-protein complexes are chemically and biologically special systems, for which there are no specifically tailored parameters in any currently available force field. Proteins and nucleic acids are chemically different which has led to force fields being developed for them separately or making compromises in the form of all-atom force fields. The comparison of force fields presented here is not perfect as it is missing CHARMM36 force field that has been discussed recently in the context of RNA-protein complexes . This, and other weaknesses are discussed in Supporting Information Part 6.