Thu, A ChimeraX equivalent would be from chimerax.atomic import AtomicStructure structure_list = session.models.list(type=AtomicStructure) The chains are in a structure's "chains" attribute. Best, Tony ________________________________ From: ChimeraX-users <chimerax-users-bounces@cgl.ucsf.edu> on behalf of Thu Nguyen via ChimeraX-users <chimerax-users@cgl.ucsf.edu> Sent: Monday, July 25, 2022 7:43 AM To: chimerax-users@cgl.ucsf.edu <chimerax-users@cgl.ucsf.edu> Subject: [chimerax-users] Question about commands similar to openModel in Chimera [EXTERNAL SENDER - PROCEED CAUTIOUSLY] Good morning, I am editing a python script that previously used the command chimera.openModels.list(modelTypes=[chimera.Molecule])to return a list of open molecules. Do we have a similar command in ChimeraX or is there any other way to get a list of protein chains in ChimeraX? Thank you very much. Best regards, Thu