Re: [ccp4bb] Substituting zero vs. Fc for unobserved reflections

2012-03-28 Thread Gregg Crichlow
Thank you for your responses. Actually, the data are very complete: 99.6% total and 99.2% in the high resolution shell. Only 2% of data were used for cross validation because there were a large number of reflections. I had calculated omit maps. At first when I discovered the presence of the lower

Re: [ccp4bb] Substituting zero vs. Fc for unobserved reflections

2012-03-27 Thread Craig Bingman
I would be concerned about the completeness of the data if adding Fcalc values has such a large effect on the appearance of this electron density.

Re: [ccp4bb] Substituting zero vs. Fc for unobserved reflections

2012-03-27 Thread Ethan Merritt
[Snipped from the full message, which is appended below] > The program that kept showing me two forms bound was not > substituting Fcalc for unobserved reflections. So, I turned on the option > to substitute Fcalc, and the minor form disappeared � the density looked > like it did in the second pro

[ccp4bb] Substituting zero vs. Fc for unobserved reflections

2012-03-27 Thread Gregg Crichlow
Please excuse me for bringing up an old issue. I have an interesting example of a difference seen when DFc was substituted for missing reflections versus when it wasn¹t. Maybe others had this experience. I had a structure in which the electron density showed two Œoverlapping¹ ligands bound in the