Run cad to merge the mtz files ( Reflection utilities) (And make sure the labels are different..) Then there is a Clipper utility which compares phases and makes all the appropriate origin shifts etc..) Eleanor # yang li wrote: > Hi All: > Now I have two sets of data from the same crystal, and I want > to calculate the > phase difference of them. Anyone knows if there are programs that can > calculate > it from two .mtz files? > > Thanks > Li Yang > >