Dear ChimeraX users, I am trying to follow this tutorial to get the proper residues: http://zarbi.chem.yale.edu/ligpargen/gmx_tutorial.html I have found chimera (0.4.7) as pip module, but it's written in python2 and therefore no longer maintained. Is there a chimerax module I can import? Pychimera is also available and could install it with python2, but it also show compatibility problems with python3 Is DockPrep a separate module? I have found this thread on the chimera forum which doesn't really answer the question: http://plato.cgl.ucsf.edu/pipermail/chimera-users/2014-July/010115.html Generally, how do I get unknown/custom residues (from LigParGen in this case) for Gromacs input files. Thank you for your support Marco ------------------- Marco Di Gennaro University of Liege