[Wien] Questions on high spin and low spin FCC-Fe

[Vladimir Timochevski]

Dear Shunli Shang,

LS and HS phases in FCC Fe have different lattice parameters (about 6.59
and 6.88 a.u.). 
So, to catch a LS phase you need to take a small lattice constant (about
6.3 a.u.) and to increase it until you get a parabola with a magnetic
moment of about 1.0 in the minimum.
To catch a HS phase you do the same procedure, but taking a big lattice
constant of about 7.1 a.u. and further decreasing it until you get
another parabola with a moment of about 2.6 in the minimum.
You also need to use GGA (I used PBE96) XC-functional.
I think you do not need to make any changes in *.inst file (use
default).

Good luck,
Vladimir.
 

> Shunli Shang wrote:
> 
> Dear Wien users,
> 
> I am trying to calculate the properties of FCC-Fe with high spin and
> low spin. But I don?t know how to describe the high-spin and low-spin
> configurations of FCC-Fe in WIEN2K.  I would be most grateful if
> someone could tell me how to do it.
> 
> Using the default ?inst? files of Fe, the results I got are the same
> as the results of High-Spin fcc Fe shown in the literature (Phy Rev B,
> Vol.60, P3839, they also used the wien code). Using the try and error
> method, I changed the ?inst? file (see below), and I happen to get
> almost the same results of low-spin state shown in literature (PRB,
> V60, P3839).
> 
> --------the default inst file given by wien2k -------
> Fe
> Ar 3 5
> 3, 2,2.0  N
> 3, 2,2.0  N
> 3,-3,2.5  N
> 3,-3,0.0  N
> 4,-1,1.0  N
> 4,-1,0.5  N
> ****     End of Input
> ****     End of Input
> 
> --------the changed inst file ----------------------
>  Fe
> Ar 3 5
> 3, 2,2.0  N
> 3, 2,1.0  N  <===== change
> 3,-3,2.5  N
> 3,-3,1.0  N  <===== change
> 4,-1,1.0  N
> 4,-1,0.5  N
> ****     End of Input
> ****     End of Input
> -----------------
> 
> Now, my questions are:
> If the default ?inst? file is for high-spin Fe, and the changed ?inst?
> file is for low spin state?
> If yes, could you please tell me the physics meaning?
> If not, then, how to describe the high spin and low spin states of
> FCC-Fe?
> 
> Thanks for your help!
> 
> Best regards,
> Shang Shunli
> 
> ********************************************************
> Dr. Shunli Shang
> Laboratory of Materials Science
> Delft University of Technology
> Rotterdamseweg 137, 2628AL, Delft
> The Netherlands
> Tel:  +31-15-278 8397
> Fax: +31-15-278 6730
> 

-- 

---------------------------------------------
Vladimir Timoshevskii
Departement de Physique, Universite de Montreal
C.P.6128, succ. Centre-Ville, 
Montréal (Québec) Canada, H3C 3J7 
Tel.: +1 (514) 343 611 - 4226
email: Vladimir.Timochevski at umontreal.ca
---------------------------------------------