It would be helpful if I finished my own sentences. As an aside for those who feel that capillary mounting is a lost art among the newer generation I assure you it isn't. All you need is a busted cryo system and a crystal backlog to get past the intimidation factor.
Katherine On Wed, Jun 6, 2012 at 2:34 PM, Jacob Keller <j-kell...@fsm.northwestern.edu > wrote: > But the edges for I and Hg are pretty far from CuKa (see attached). I > am familiar with their being extra signal (white lines) very close to > the peak, but not so far away.... > > JPK > > > > On Wed, Jun 6, 2012 at 2:15 PM, Bernhard Rupp (Hofkristallrat a.D.) > <hofkristall...@gmail.com> wrote: > > There is also a relevant point from the physics of the absorption > spectra - > > the XANES white lines (near edge peaks higher than the continuum > transition > > or edge step) depend on the chemical environment of the anomalous atom in > > terms of available unoccupied states (which n. b. is something entirely > > different that the local neighbor environment/geometry which can be > > backtransformed - although with quite some uncertainty - from the EXAFS > > wiggles). > > > > Any argument about absolute f" peak values in absence of experimental > > evidence (scan) might want to consider that..... > > > > Best, BR > > > > -----Original Message----- > > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of > Jacob > > Keller > > Sent: Wednesday, June 06, 2012 11:30 AM > > To: CCP4BB@JISCMAIL.AC.UK > > Subject: Re: [ccp4bb] Fun Question - Is multiple isomorphous replacement > an > > obsolete technique? > > > > No offense taken (we all have our dour moments!), but grant me a sincere > > question: the f" occupancy value would have been just as close at 11 as > 5 if > > the true value were 8, am I correct? In other words, do you imply by > saying > > "doing well" that you got as *much* as 5, or that you got as *close* as > 5? I > > am just trying to see whether I understand these things correctly. > > > > Jacob > > > > > > > > On Wed, Jun 6, 2012 at 12:21 PM, Gerard Bricogne <g...@globalphasing.com > > > > wrote: > >> Dear Jacob and all, > >> > >> I realise that my last statement sounds awfully dour and > >> dismissive, in a way I really didn't intend. Especially as Stefan's > >> original posting was a "Fun Question". > >> > >> Apologies to all for this over-the-top statement. I enjoyed a lot > >> of the replies. > >> > >> > >> With best wishes, > >> > >> Gerard. > >> > >> -- > >> On Wed, Jun 06, 2012 at 06:09:33PM +0100, Gerard Bricogne wrote: > >>> Dear Jacob, > >>> > >>> I thought that getting 5 for each iodine was doing pretty well, > >>> given the circumstances - e.g. the noisy measurements, the primitive > >>> software running on slow computers with tiny amounts of memory, etc. . > >>> > >>> In any case my main point, directed at the original poster, was > >>> that reading the early Acta Cryst. issues ("RTFL") might be an > >>> alternative and perhaps more enlightening way of getting a picture of > >>> the evolution of phasing methods than finding some clever filter > settings > > in the RCSB ;-) . > >>> > >>> > >>> With best wishes, > >>> > >>> Gerard. > >>> > >>> -- > >>> On Wed, Jun 06, 2012 at 11:08:37AM -0500, Jacob Keller wrote: > >>> > ...Even with such primitive techniques, I can remember an HgI4 > >>> > > derivative in which you could safely refine the "anomalous > > occupancies" > >>> > > (i.e. f" values) for the iodine atoms of the beautiful planar > >>> > > HgI3 anion to > >>> > > 5 electrons. > >>> > > >>> > I am surprised--f"'s of I and Hg are supposed to be around 8 for > >>> > CuKa (or maybe you weren't using CuKa)? > >>> > > >>> > JPK > >>> > > >>> > > >>> > -- > >>> > ******************************************* > >>> > Jacob Pearson Keller > >>> > Northwestern University > >>> > Medical Scientist Training Program > >>> > email: j-kell...@northwestern.edu > >>> > ******************************************* > >> > >> -- > >> > >> =============================================================== > >> * * > >> * Gerard Bricogne g...@globalphasing.com * > >> * * > >> * Global Phasing Ltd. * > >> * Sheraton House, Castle Park Tel: +44-(0)1223-353033 * > >> * Cambridge CB3 0AX, UK Fax: +44-(0)1223-366889 * > >> * * > >> =============================================================== > > > > > > > > -- > > ******************************************* > > Jacob Pearson Keller > > Northwestern University > > Medical Scientist Training Program > > email: j-kell...@northwestern.edu > > ******************************************* > > > > > > -- > ******************************************* > Jacob Pearson Keller > Northwestern University > Medical Scientist Training Program > email: j-kell...@northwestern.edu > ******************************************* >