Dear Eleaonor and CCP4ers,
I always wondered, why there are phase columns PHWT, PHDELWT (Refmac)
or PH2FOFCWT, PHFOFCWT (phenix.refine) in addition to the PHIC column
of the atomic model. In absence of other phase information, the phase
should come from the atomic model, only.
Best
Well, it makes for consistency between the output when there is not, and
is, exptl phase information - in the 2nd case the PHWT is a weighted
derivative of the two phase estimates.
You could get away with just one of PHWT and PHDELWT since they can
only differ bu 180, but that would require
The SIGMAA program has since it was written in the 80's (mainly by Randy
of course, but also in part by Eleanor I believe?) used only 1 phase
column (= PHIC) for the case where the phases of FWT DELFWT are equal
to PHIC: obviously if they are unequal (e.g. as a result of phase
combination) then
Zitat von George DeTitta deti...@hwi.buffalo.edu:
I'd appreciate it if people could tell me their experiences with what I
would call phantom crystals, or ghost crystals. These are objects
that display the seeming morphology of crystals (clear facets, sharp
edges)
... There is also a second
A PhD position in structural biology is available in the group of
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A few more examples of what Daniel refers to can be seen in Figure 11 - Nature
Protocols 4:706-731, 2009. We encounter them from time to time using the in
meso (lipidic cubic phase) method. With experience you get to recognize them
for what they are.
Martin
-Original Message-
From:
Tim,
Not really. Fo's can be viewed as having 3 parts. 1) F from our modeled
structure, 2) F from what we can't model. This can be bulk solvent, partial
or multiple occupancies in low resolution structures, thermal anisotropy ,
etc. 3) F from random errors in measuring data. The first F is what
Phantom Crystals can easily be achieved by failing to cryoprotect most
any crystal, or by a few other common crystal handling methods, but I
don't think this is what you were asking about.
I do have users bring in what I call plastic crystals from time to
time, but these crystals that don't
Hello Doug,
I understand your arguing, although I do not understand why Fo contains a
contribution from the model(led structure). My idea was only supposed to
be a backup in case the apo-form had not been measuredcor could not be
used. I agree the Fo(complex)-Fo(apo) gives a much more
