[Wien] AFM

Helen Müller muech at cup.uni-muenchen.de
Wed Jul 21 14:21:48 CEST 2004


Dear WIEN users,
I have a problem with the LDA+U calculation for GaV4S8. U = 8 eV. GaV4S8 is an 
antiferromagnetic compound, but only the V atoms are antiferromagnetic 
arranged, Ga and S atoms are non-spinpolarized. Space group No. 115, P-4m2, 
a=13.64 Angström, c=9.65 Angström.
So I have changed the GaV4S8.inst file, and now the spin occupation is :
V 1       
Ar 2 5
3, 2,2.0  N
3, 2,1.0  N
4,-1,1.0  N
4,-1,1.0  N
V 2       
Ar 2 5
3, 2,2.0  N
3, 2,1.0  N
4,-1,1.0  N
4,-1,1.0  N
V 3       
Ar 2 5
3, 2,2.0  N
3, 2,1.0  N
4,-1,1.0  N
4,-1,1.0  N
V 4       
Ar 2 5
3, 2,1.0  N
3, 2,2.0  N
4,-1,1.0  N
4,-1,1.0  N
V 5       
Ar 2 5
3, 2,1.0  N
3, 2,2.0  N
4,-1,1.0  N
4,-1,1.0  N
V 6       
Ar 2 5
3, 2,1.0  N
3, 2,2.0  N
4,-1,1.0  N
4,-1,1.0  N
Ge 1       
Ar 5 5
3, 2,2.0  N
3, 2,2.0  N
3,-3,3.0  N
3,-3,3.0  N
4,-1,1.0  N
4,-1,1.0  N
4, 1,1.0  N
4, 1,1.0  N
4,-2,0.0  N
4,-2,0.0  N
Ge 2       
Ar 5 5
3, 2,2.0  N
3, 2,2.0  N
3,-3,3.0  N
3,-3,3.0  N
4,-1,1.0  N
4,-1,1.0  N
4, 1,1.0  N
4, 1,1.0  N
4,-2,0.0  N
4,-2,0.0  N
S 1       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 2       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 3       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 4       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 5       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 6       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 7       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 8       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 9       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 10      
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 11      
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 12      
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
****     End of Input
****     End of Input

But the MMI for Ga1=-0.59245 and MMI for Ga2=0.46722. It is physical 
impossible. MMI's for Ga atoms should be very small, like for the S atoms.

The over possibility for the spin occupation is:

V 1       
Ar 2 5
3, 2,2.0  N
3, 2,1.0  N
4,-1,1.0  N
4,-1,1.0  N
V 2       
Ar 2 5
3, 2,2.0  N
3, 2,1.0  N
4,-1,1.0  N
4,-1,1.0  N
V 3       
Ar 2 5
3, 2,2.0  N
3, 2,1.0  N
4,-1,1.0  N
4,-1,1.0  N
V 4       
Ar 2 5
3, 2,1.0  N
3, 2,2.0  N
4,-1,1.0  N
4,-1,1.0  N
V 5       
Ar 2 5
3, 2,1.0  N
3, 2,2.0  N
4,-1,1.0  N
4,-1,1.0  N
V 6       
Ar 2 5
3, 2,1.0  N
3, 2,2.0  N
4,-1,1.0  N
4,-1,1.0  N
Ge 1       
Ar 5 5
3, 2,2.0  N
3, 2,2.0  N
3,-3,3.0  N
3,-3,3.0  N
4,-1,1.0  N
4,-1,1.0  N
4, 1,1.0  N
4, 1,0.0  N
4,-2,0.0  N
4,-2,1.0  N
Ge 2       
Ar 5 5
3, 2,2.0  N
3, 2,2.0  N
3,-3,3.0  N
3,-3,3.0  N
4,-1,1.0  N
4,-1,1.0  N
4, 1,1.0  N
4, 1,0.0  N
4,-2,0.0  N
4,-2,1.0  N
S 1       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 2       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 3       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 4       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 5       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 6       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 7       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 8       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 9       
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 10      
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 11      
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
S 12      
Ne 3 5
3,-1,1.0  N
3,-1,1.0  N
3, 1,1.0  N
3, 1,1.0  N
3,-2,1.0  N
3,-2,1.0  N
****     End of Input
****     End of Input

But now the MMI for Ga1=-0.53399 and Ga=0.43232. And it is although physical 
impossible. 

Can I choise some other spin occupation for Ga1 and Ga2 ?  Or you have some 
other ideas, what I can try to do?

Best regards, Helen.





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