Dear Haiping, Can you open the .mrc file in Coot? I'm not a Coot user, but as far as I understand, it can read map files directly, whereas opening an .mtz file does some additional calculations to create a new map. Chimera MRC output may be accepted as CCP4 format: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/volumeviewer.html#mrcout> Coot manual "From a CCP4 map use File -> Read Map" <http://www2.mrc-lmb.cam.ac.uk/personal/pemsley/coot/web/docs/coot.html#Create-a-Map> You might trying renaming the .mrc as .map to make this work, if it doesn't already. I haven't tried the process, it is just a guess from reading the manuals. Best regards, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Jun 18, 2014, at 6:11 AM, #ZHANG HAIPING# wrote:

Dear chimera user: I have a .mrc file generated by chimera, now I want to convert it to .mtz formate, so I can load to coot, and examine the structure in details. Can anyone tell me how to convert .mrc to .mtz? Best regards, Haiping