Dear Filip, concerning XDSCONV: if FRIEDEL'S_LAW=FALSE, using filetype of CCP4, you get F,SigF,DF,SigDF,isym using filetype CCP4_F, you get F,SigF,F(+),SigF(+),F(-),SigF(-) using filetype CCP4_I, you get IMEAN,SIGIMEAN,I(+),SIGI(+),I(-),SIGI(-) so you can (and should) directly output from xdsconv what you need for a downstream program. A short explanation is at http://strucbio.biologie.uni-konstanz.de/xdswiki/index.php/Xdsconv Detailed explanation of each format is at http://homes.mpimf-heidelberg.mpg.de/~kabsch/xds/html_doc/xdsconv_formats.ht... HTH, Kay