2) One can get (Fcalc, phi_calc) to certain resolution and completeness first and then do the Fourier transformation. In this case you will get a Fourier image of the "true" electron density (for example, calculated in "1)") at given resolution and completeness. Obviously, as higher resolution and completeness, as closer this Fourier image to the "true" density. This is possible to do with phenix.refine and the following command will do this: Please note that the Fourier image calculated in this example will be based on the resolution and completeness of provided Fobs (data.mtz) (will be not exactly what one can get with formulas rho(r)=...).If I understand this correctly then using CCP4 unique to create a complete MTZ file with the correct spacegroup and unit cell parameters and a high resolution, would allow me to work around this and approach something closer to rho(r)=... right? Thanks for your help, James _______________________________________________ phenixbb mailing list [email protected] http://www.phenix-online.org/mailman/listinfo/phenixbb