[Wien] spin distribution in organic

[thomas.mazet]

Dear Hai,

 I will only give you partial experimental information about spin density 
in organic compounds : I know that a group from Grenoble (France) 
including J. Schweizer and E. Ressouche has studied the spin density in 
organic phases from polarized neutron experiments. Maybe you should try 
to find some of their publications on the web and have  look at their 
experimental results.

Thomas


> Dear sir:
>     I have a larger organic system (36 inequivalent atoms per unit cell ) 
> and want to study the magntic character of it. The experiment has shown 
> that there is about 1.0 ¦ÌB/mol for the  magnet moment. From the spin 
> polarization calculation , I found that the  magnet moment of one molecule 
> is  1.00¦ÌB, which is in agreement with the experiment. But there is a 
> larger spin population in the interstitial region. For example: the sum of 
> spin populations on all atoms is about 0.58¦ÌB/mol, while the spin 
> population in the interstitial region is about 0.42¦ÌB/mol.   I don not 
> know if this is correct or possible. 
>    I want to know the reason of it :
>      1: if this is because of the samll MT sphere  or other inappropriate 
> parameters used in the  calulation?. 
>      2: or it is due to the fact that there is no localized spin center in 
> the organic material  because of the hyperconjugation effect,while the 
> calculated spin populatoin on the atom is confined in the MT sphere,  so 
> the spin population in the interstitial region  is larger?
>      3: I want to know the spin distribution in the molecule space. If 2 is 
> correct, is it  appropriate to  plot the spin electron density  (the spin 
> up electrons minus spin down  electron) to represent the spin distribution 
> in the molecule? 
> 
>  The parameters I used in the calculation : 
>    The RMT for H is 0.6,  and the RMTs for O, C, N are  1.1-1.2
>    RKmax=2.5 , Gmax=20 and 10 k-points in the IBZ
> 
>    It wil be very grateful If some can help me or give me  advice about it 
> .
> 
> 
> Best wishes
> 
> Hai
> 
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-- 
Thomas MAZET
Laboratoire de Chimie du Solide Minéral (UMR 7555)
Université Henri Poincaré-Nancy I
BP 239 54506 Vandoeuvre les Nancy Cedex
FRANCE
Tel.: +33-(0)3-83-68-46-77
Fax : +33-(0)3-83-68-46-11