>> I am not sure that there is any such thing as an up-to-date estimate of >> the prevalence of anisotropy in the PDB - but now you can get a feel for it >> yourself by looking at any entries you want. However please do not submit >> the whole PDB to the server - yet ;-) .
It would be great to have a figure showing distributions of anisotropy across the pdb, perhaps filtering for various parameters like resolution, lattice size, membrane proteins, etc. And this should be helpful for assaying the importance of dealing with anisotropy using STARANISO and others. >> From looking at anisotropy as visible through the overall scaling >> Debye-Waller factor, I would say that whenever anisotropy is allowed by the >> Laue group, it will be present, even if mild. Symmetry lower than cubic >> means that intermolecular contacts along directions that are not >> symmetry-equivalent will be different, and there is no reason why different >> contacts should create identical degrees of long-range order. Yes, that makes all the sense in the world. I wonder how one would evaluate in a given case whether the usual isotropic approximation is good enough? Or perhaps there's no reason to use the isotropic assumption at all, now that there are ways of dealing with anisotropy? JPK
