Re: [sdpd] I have a problem.

[Neeraj <neeraj...@jncasr.ac.in>]

Thanks a lot for your suggestion Prof. Le Bail. I'll surely try to do
these bond-valence calculations. I'm not sure if there is any chance at
all to have Cl and K occupying the same site even due to disorder.
Chemically they differ, even though their respective ions (anion and
cation) may not crystallographically.
 
My earlier thinking was that there could be a mobile proton somewhere in
the structure which may be balancing the negative charge of chloride
anion but such a proton if present in the structure would be too acidic,
and will destroy the structure. Since there are no other peaks of
sufficient weights are left in the fourier map, I don't know what should I
conclude and simple X-ray will not  tell me about this proton if present
at all. Can you say something more on this? 

Secondly are there any reports of charged species crystallized where
counter-ion is not present in the structure? This sounds quite absurd to
me myself but I just came to this crazy thought. I understand that if such
a charge were present then in the whole extended lattice it would lead to
too much of unbalanced charge and the structure will definitely collapse.

--------------------------------------------------------------------------

> >The total formula does not show the charge neutrality of the structure.
> 
> If not already done, perform some valence bond calculation and
> see if there is not some problem in another place than your K
> atom position which has few if no chance to permute with Cl.
> 
> Best,
> 
> Armel Le Bail - Université du Maine, Laboratoire des Fluorures,
> CNRS ESA 6010, Av. O. Messiaen, 72085 Le Mans Cedex 9, France
> http://www.cristal.org/
> 
> 
> ------------------------------------------------------------------------
> Old school buds here:
> http://click.egroups.com/1/4057/5/_/40740/_/959445441/
> ------------------------------------------------------------------------
> 
>