[sdpd] A problem

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

Dear all,

I have an extended structure where apart from organic host their are
sodium and chloride ions as guest. The peculiar problem I'm facing is that
sodium site refines well and gives reasonable thermal parameters only when
I assign partially occupancy of chlorine in that site. The site has at
present 1/7th occupancy of chlorine and 6/7th occupancy of sodium ion. My
problem is that, whether such things are known where cation and anion have
fractional occupancies like this and are present at the same site. I
suppose one can call it doping of chlorine in sodium site. If that is the
case, then how can one visualise such a structure. What physical meaning
one can get from such fractional occupancies of cation and anion at the
same sight. Secondly, is such a thing does exist, in what crystallographic
parameters does it reflect itself, other than thermal parameters?

Thanks a lot in advance to any forthcoming suggestion. 

regards
neeraj


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                               S. NEERAJ
                       INTEGRATED PhD. CHEMISTRY
                          CERAMICS LABORATORY 
                 CHEMISTRY AND PHYSICS OF MATERIALS UNIT
             JAWAHARLAL NEHRU CENTER FOR ADVANCED SCIENTIFIC
                                 RESEARCH
                         JAKKUR, BANGALORE 560064
               
		  phone : 0091-80-8462751 
		  fax   : 0091-80-8462766
	       
	               e-mail: neeraj...@jncasr.ac.in

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