Warning, anecdote ahead! (and this wasn't the point of my original post...)
I get better (flatter difference plot) fits with SRM676A using charged
atoms (Al+3, O-2) than I do with neutral. (Co Ka, lab BB diffractometer)
https://imgur.com/a/83s1Bpz (sqrt scale)
I intend on looking in more depth (
Brian,
That's right. The only reason to use O2- form factor is to model disordered
water molecules (e.g. when H atoms cannot be located) since O2- has the
same number of electrons as H2O. BTW: I saw somewhere extrapolated form
factor for H2O which would be even better for this purpose.
Peter
..
I am going to make the comment that (A) neutral atom form factors are probably
closer to the actual electron distribution in most materials where there is
significant covalent bonding (~= almost everything) and (B) even if that were
not true, the difference between O, O1- and O2- is probably pre
Hi Matt,
I include below three references in which we demonstrate the inadequacies of
the oxygen form factor used by powder diffraction software (top two refs) and
by single crystal diffraction software (last ref).
In both the powder and the single crystal work, it was found that there were
cl
Thanks all
It looks like fat fingers all around!
W&K doesn't contain O2-, does contain O-
RR&G _does_ contain O2-, doesn't contain O- (every version of the waasameir
data I've found online has this typo, so I'm pretty sure they're all the
same file.)
Now just to cross-check the data to see if th
Hello Daniel, hello all!
Daniel, you are right. I just obtained the Hovestreydt paper, he actually
published a 9 coefficients representation.
My apologies!
Cheers,
Arnt
-Bruker Confidential-
Von: rietveld_l-requ...@ill.fr Im Auftrag von
Többens, Daniel
Gesendet: Dienstag, 21. Februar 2023
Sorry, while complaining about a content-relevant typing error, I made a
content-relevant typing error myself. The paper of Rez does contain
values for O2-, but not for O1-.
Am 21.02.2023 um 09:57 schrieb Többens, Daniel:
Hello Arnt,
I believe you are probably mistaken. The file at GitHub cit
Hello Arnt,
I believe you are probably mistaken. The file at GitHub cites at the
source of most of its scattering factors either the paper of Waasmaier &
Kirfel ("New Analytical Scattering Factor Functions for Free Atoms and
Ions", D. Waasmaier & A. Kirfel, Acta Cryst. A 95) or the Internation
