Dear Phenix users, <br>My question may have been asked before.<br>I am refining a structure containing calcium ions. <br>I am wondering if the program considers it to be divalent Ca++ or neutral calcium atom. <br>It seems that the ion and neutral atom have different atomic scattering factors.<br><br>Thanks<br><br>Chen<br><BR><BR>Chen Chen, PhD, Research Associate<br>Center for Advanced Research in Biotechnology (CARB),<br>University of Maryland Biotechnology Institute (UMBI),<br>9600 Gudelsky Drive, Rockville, MD 20850<br>240-314-6122 </BR></BR>