[phenixbb] superpose CryoEM map onto an Xray map?

Dear all, I am trying to superpose a CryoEM map onto a Xray map. I tried the "superpose maps" under the map section of phenix 1.14 but it only takes "reflections" and not the .mrc format  of the CryoEM map. should I transform the CryoEM map into structure factors using "Map to structure factors" or is there a better way to do this? Thank you for your feedback. Best Vincent -- Vincent Chaptal, PhD MMSB -UMR5086 Drug Resistance and Membrane Proteins Laboratory 7 passage du Vercors 69007 LYON FRANCE +33 4 37 65 29 01 http://mmsb.cnrs.fr/en/