Force fields. Finally, some features are meant to facilitate force field development and the implementation of selected methods such as solute tempering (REST2) . These include the possibility of automatically cloning types along with all their bonded interaction parameters and renaming all selected atoms to the new type, or by automatically adding NBFIX-type modifications just by specifying the deviation from the standard Lorentz-Berthelot rules . An additional module implements a generic strategy for multiple dihedral fitting to QM data, akin to that available in the FFTK module of VMD for NAMD topologies .