Re: [phenixbb] Geometry Restraints - Anisotropic truncation

Hi Kendall, A caution on using the free R value to evaluate the utility of applying an anisotropic truncation to the data: As you remove data with low I/sigma, you will generally improve the free R regardless of whether your model is improved or not. This is of course true also if you simply remove all the data with I/sigma < 3 or apply any other truncation of that type. All the best, Tom T ________________________________________ From: [email protected] [[email protected]] on behalf of Kendall Nettles [[email protected]] Sent: Tuesday, May 01, 2012 11:34 AM To: PHENIX user mailing list Subject: Re: [phenixbb] Geometry Restraints - Anisotropic truncation I have seen dramatic improvements in maps and behavior during refinement following use of the UCLA anisotropy server in two different cases. For one of them the Rfree went from 33% to 28%. I don't think it would have been publishable otherwise. Kendall On May 1, 2012, at 11:10 AM, Bryan Lepore wrote:

On Mon, Apr 30, 2012 at 4:22 AM, Phil Evans wrote:

...

Are anisotropic cutoff desirable?

is there a peer-reviewed publication - perhaps from Acta Crystallographica - which describes precisely why scaling or refinement programs are inadequate to ameliorate the problem of anisotropy, and argues why the method applied in Strong, et. al. 2006 satisfies this need?

-Bryan _______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb

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