Dear Modeller: I have heme modeled into my target using Modeller. When I try to visualize the model, the Fe is not shown. I check the pdb file of the model, Fe is there. I couldn't understand what could be wrong. Why can't "Fe" be visuallized? I use Modeller 8v1. The program used for structure visuallization are Chimera and VMD. Thank you for your advice. Bo