Dear Yu I cannot say about other programs. refmac uses equation in slides No 13-14 of the presentation: http://www.ysbl.york.ac.uk/refmac/Presentations/ Refmac_Erice_workshop.ppt
If your crystal is a perfect twin and you have processed data in true space group then refmac will give map for a single crystal. However accuracy of results have never been analysed. Moreover I would be very careful in the beginning of refinement (i.e. immediately after molecular replacement with high R factors). In these cases twin fraction refinement and map coefficients may not be as reliable as they should be. regards Garib On 15 Dec 2010, at 17:25, zhang yu wrote: > > Dear all, > > I have a question about twin refinement of Refmac in CPP4. I was told that > the refmac (Phenix also?) will generate the detwined map after the refinement > with twin. My question is that If my crystal is a perfect hemihedral twin, > how can the refmac make a detwined map after the refinement? > > Thanks > > -- > Yu Zhang > HHMI associate > Waksman Institute, Rutgers University > 190 Frelinghuysen Rd. > Piscataway, NJ, 08904 > >
