This is the basis of the TAILS "correction" in Scala, but I'm not convinced it works very well, particularly if you don't have lots of fully recorded reflections Phil
On 28 Jan 2010, at 15:41, Dirk Kostrewa wrote: > Dear James, > > Am 27.01.10 10:08, schrieb James Holton: > <snip> >> I'm still not really sure what the difference is between a Bragg spot and a >> feature "under" it. Why not define a "Bragg intensity" operationally? >> Subtracting local background with a least-squares plane is pretty much >> universally done, and as long as the disorder is uncorrelated, the >> intensities obtained this way really are those of the partial-occupancy >> models we currently build. It is when this assumption breaks down that we >> need a "correction factor". > </snip> > > Since diffuse scattering leads to long tails around the Bragg spots, there > was an interesting approach by Bob Blessing some time ago to fit a kind of > triangular background under the (2D-)spots from an empirical least-squares > analysis of the diffuse scattering in these long tails and subtract this > background from the total intensities. To my knowledge, his approach hasn't > gone into any data processing program (maybe in Bob Blessing's DREAR - but I > don't use it). Here is the reference: > > "Data reduction and error analysis for accurate singel crystal diffraction > intensities", Robert H. Blessing, Cryst. Rev., Vol. 1, pp 3-58 > > Best regards, > > Dirk. > > ******************************************************* > Dirk Kostrewa > Gene Center, A 5.07 > Ludwig-Maximilians-University > Feodor-Lynen-Str. 25 > 81377 Munich > Germany > Phone: +49-89-2180-76845 > Fax: +49-89-2180-76999 > E-mail: [email protected] > WWW: www.genzentrum.lmu.de > *******************************************************
