[Wien] Fwd: problem in hyperfine field of Gd

[Pavel Novak]

Dear Mohanta,

your calculation is correct. Your result is caused by the failure of LSDA, 
GGA, as they underestimate the core contribution to hyperfine field.

Regards
Pavel


 On Fri, 13 Nov 2009, susanta mohanta wrote:

> Dear  Prof. Blaha andWien Users,
> We  are working in some rare-earth systems. We have made calculations
> with R_mt=2.9, RKmax=9.5 and k-mesh=20x20x11. For Pure Gd we are getting
> most of
> the physical properties like unitcell parameters (optimized with GGA and
> GGA+U+SO) consistent with some of the recent calculations using wien2K as
> well as experiment. Howerver, we find that the hyperfine field is positive;
> +270KG
> with core HFF = -2893kG and HFF_val= +3163kG (in case of GGA) and +223kG
> with
> HFF_core= -2931kG and HFF_val= +3154kG(incase of GGA+U with U_eff = 0.6).
> The experimental value for HFF of Gd in Gd is reported to be -350kG. The
> negative sign is what one would expect for the spin only moment of Gd. We
> made
> calculations with U_eff ranging from 0.4 to 0.7, Rmt changing from 2.6 to
> 3.0,
> RKmax from 8 to 10 but the sign of HFF always comes to be positive.
> While, magnitude may be acceptable, can some one clarify why the sign comes
> out opposite. Am I making some trivial mistake.
> 
> we are working with wien2k9.1 version. We fell valence contribution is over
> estimated.
> Any suggestion in this regard ?
> 
> with sincere regards
> susanta
> 

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