Hi Pavel,

Thank you for responding to my question so eloquently.
But there are still something confusing me.
First of all, when I used coot to open the "_map_coeffs.mtz", only two maps were displayed in the window,not four?
Second, how to choose the maps coefficients? In phenix documentation, we konw that any specified coefficients can be set, for example: 2mFo-DFc, 2.7mFo-1.3DFc, Fo-Fc, 3Fo-2Fc. but it do not tell us why we should choose different coefficients.
Thanks a lot.

dream830106