Appropriate CVs for WT-METAD to capture docking-undocking study of a nucleic acid

[Sk Habibullah]

Dear plumed users,

        I want to do well-tempered metadynamics simulation to capture docking-undocking study of a nucleic acid. What will be best CVs I can use for this case? Please let me know. I have tried with eRMSD (which can capture the orientation of residues) and distance between two parts of nucleic acid.  But eRMSD considering many residues (15 residues) is a very slow CV. What else CV can I use to consider both orientations and tertiary contacts between different residues? I have thought about contact map CV, but there I need to consider many pairs to capture tertiary contacts between different residues. Will this contact map CV not be very slow for convergence?? 

Thank you in advance,

Habibullah