[phenixbb] heavy atoms

Hi, I am dealing with a complex structure which the ligand contains a atom Iodine, I guess it's because Iodine is heavy atom, the electron density of Iodine turns red after 5 cycles refinement. Anybody coped with similar issue? How to let phenix know that the Iodine atom is part of the ligand? Best, Tiantian -- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences Address: Room 101, 646 Songtao Road, Zhangjiang Hi-Tech Park, Pudong New Area, Shanghai, 201203, P.R. China