[Pw_forum] regarding to calculate oxidation state

[Giuseppe Mattioli]

Dear Rajkamal.A.
"Oxidation state" is a chemical concept, that is, a literally meta-physic 
(beyond nature) concept. :-)
In the case of DFT calculations you should first choose a charge 
partitioning scheme, which is a (somewhat arbitrary) method to assign 
charge density to atoms. There are many possible approaches: Lowdin, 
Mulliken, Bader, ... But you will rarely obtain a net charge like 2.0 or 4.0 of 
a Mn(II) or Mn(IV) site in the case of solid state compounds, for a series of 
good reasons that I cannot explain here. Nevertheless you can calculate 
*trends* in charge populations that (if you are not out of luck) lead you to 
assign "oxidation states" to atoms. You may want to read the following 
papers which can enlighten you on this interesting problem:

Raebiger, H.; Lany, S.; Zunger, A. Nature 2008, 453, 763.
Bo Wang, Shaohong L. Li, and Donald G. Truhlar J. Chem. Theory Comput 
2014, 10, 5640

An interesting example regarding Mn oxides is contained in the SI of my 
recent paper

J. Am. Chem. Soc. 2015, 137, 10254

HTH
Giuseppe


On Wednesday, September 30, 2015 10:18:35 PM Raj kamal wrote:
> dear QE experts
>         i am working on Lithium ion batteries. In this  i need to calculate
> oxidation state of particular atoms Mn in such as LiMn2O4 materials. 
please
> guide me how to calculate oxidation state for particular material in QE 
and
> tags which i need to use.thanks in advance.

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   Giuseppe Mattioli                            
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
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