[phenixbb] pdb hierarchy

Hi Phenix, I have a hierarchy question. I was using the hierarchy and got something that I did not expect. when running this: pdb_io = pdb.input(pdbfile) hierarchy = pdb_io.construct_hierarchy() for model in hierarchy.models(): print model.id for chain in model.chains(): print ' ' + chain.id When I do this I expect the chains in pdbfile to be printed once for each model in pdbfile. However, when I ran this I got, for example, chain 'A' printed four times under the same model. Why is this? Thanks, Bradley