Dear ChimeraX Users, I am trying to perform a morphing between two cryo-EM structures of the same complex, where one structure has twice the number of chains as the other (PDBs 3J9K and 8Y6Q). However, the larger structure causes an error during morphing. I have attempted to write a script that aligns the two structures and deletes the unmatched chains from the larger structure. Unfortunately, the script is not working as expected. from chimerax.core.commands import run def delete_unmatched_chains(session): # Get models #1 and #2 m1 = next((m for m in session.models if m.id == (1,)), None) m2 = next((m for m in session.models if m.id == (2,)), None) if m1 is None or m2 is None: session.logger.info("Model #1 or #2 not found.") return chains1 = {chain.chain_id for chain in m1.chains} chains2 = {chain.chain_id for chain in m2.chains} unmatched = chains1 - chains2 if unmatched: chain_ids = ",".join(unmatched) # Deleting unmatched chains run(session, f"delete /{chain_ids}") session.logger.info(f"Deleted chains: {', '.join(unmatched)}") else: session.logger.info("No unmatched chains found.") Could you please help me or alternatively propose another solution? Any suggestions would be greatly appreciated. Thank you in advance ! Enrico