I was hoping to minimize a homology model containing two heme groups. To understand how I might do this I have been starting with the known structure 1a6m. As suggested in the documentation I begin with Dock Prep and calculate charges etc. To my surprise Chimera alpha version 1.6 (build 34702) actually assigned charges to the heme. The problem is with the minimization itself. Within Minimize Structure I turn off all of the Dock Prep steps and simply try to minimize the structure but get an error,"Element Fe (atom #0:154.A@FE) is not currently supported". I was assuming the charge calc was going to be the hard part but now I am stuck at this subsequent step. Is there something I can do to get the heme atoms recognized or is this simply not possible? Thank you, Jon Rumbley Dr. Jon N. Rumbley Assistant Professor Dept. of Pharmacy Practice and Pharmaceutical Sciences University of Minnesota-Duluth 127 Life Sciences 1110 Kirby Dr. Duluth, MN 55812 Phone: 218-726-6047 email: jrumbley@d.umn.edu