You've most likely looked at this, but if not it might be worthwhile to check how these ripples behave while varing the low-resolution limit used (20-2.2,15-2.2, etc).
Pete > Dear friends of the Fourier transform, > > I am refining a structure with 2 adjacent Hg atoms bound to cysteines of > different monomers in the crystal contacts, which means I need to refine > them as well. While the structure nicely refines (2.2 A data), I do not > get rid of negative density ripple layers next to them (-10 sigmas). My > question: is this likely due to anistropy of the soft mercury atoms > (anisotropic B refinement decreases the ripples) or is this likely a > summation truncation effect prominent for heavy atoms? Can I just > anistropically refine the mercuries while I keep the rest isotropic? > Never saw this in a PDB. Suggestions are very welcome. > > Greetings > > Klemens Wild > Pete Meyer Fu Lab BMCB grad student Cornell University
