Yes, I just looked up the paper--seems right on topic--a powder-type ring at ~4.2 Ang, corresponding to Calpha-Calpha distances! But no 1.2-1.5 Ang ring, from what I saw. Maybe it gets swamped out by other things. I am thinking that the variety/distribution of bonds/distances of length 1-3 Ang in the crystal/mother liquor combo is so high/broad that you can't see them anymore. I wonder whether when people soak in various heavy atom clusters, they see powder rings for the HA-HA distances in the unbound clusters?
JPK On Wed, May 9, 2012 at 11:51 AM, Philip Kiser <p...@case.edu> wrote: > Hey Jacob, > > There was a paper by Robert M. Blessing et al (Acta Cryst D 1996) that > at least partially attributed the diffuse ring that one sees around > 3-4 A to something similar to what you are describing (scattering > between amide oxygen and nitrogen for example). > > Philip > > -- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program email: j-kell...@northwestern.edu *******************************************