Re: [ccp4bb] Summary : [ccp4bb] embarrassingly simple MAD phasing question

2010-10-13 Thread William G. Scott
On Oct 13, 2010, at 3:09 PM, Tim Gruene wrote: > Dear Bill, > > The discussion is becoming complicated because of the mixing of notations. > There is a theory or model which describes the atomic scattering factor as >f = f0 + f' +if" > from which the structure factor is calculated. That right

Re: [ccp4bb] Summary : [ccp4bb] embarrassingly simple MAD phasing question

2010-10-13 Thread Lijun Liu
Bill, If I understand you correctly, the problem turns to be understanding coordinate system. The coordinate system in the plot in your original email is not a complex one but a polar coordinate system [|F| and phase (polar angle)]. In order to add the contribution of an atom with anomal

Re: [ccp4bb] Summary : [ccp4bb] embarrassingly simple MAD phasing question

2010-10-13 Thread Tim Gruene
Dear Bill, The discussion is becoming complicated because of the mixing of notations. There is a theory or model which describes the atomic scattering factor as f = f0 + f' +if" from which the structure factor is calculated. That right angle that you see in the picture you sent us with that li