[Wien] Results of ferromagnetic state is same as ferrimagnetic state?

[Jinyun Li]

Dear Mr. Cottenier:
  As you mentioned, I obtained twice the ferrimagnetic solution and this frequently happens. 
In fact, I used this "flip spin configution" method to get energy difference between ferromagnetic state and ferrimagnetic state
in the past, and it seems working well. Now I wonder in what situation can this happen? And as you mentioned, I can try a 
FSM calculation to get the virtual ferromagnetic state, the magnetic moment in the unit cell I should specify is 0.00605+3.77188+0.26145+0.00538*2+0.08241*6 = 4.53855 mu_B ? Thanks.

Regards ,
Jinyun Li

----- Original Message ----- 
From: "Stefaan Cottenier" <Stefaan.Cottenier at fys.kuleuven.be>
To: <wien at zeus.theochem.tuwien.ac.at>
Sent: Sunday, October 22, 2006 9:16 PM
Subject: Re: [Wien] Results of ferromagnetic state is same asferrimagnetic state?


> 
> As your results for the magnetic moments show, you obtained twice the  
> ferrimagnetic solution. That frequently happens, it is not because you  
> specify some starting configuration in case.inst that it will end up  
> in the same configuartion after the scf cycle. If you really need the  
> ferromagnetic solution, you can try a FSM (fixed spin moment)  
> calculation, specifying a magnetic moment in the unit cell that is the  
> sum of all absolute values of the ferrimagnetic moments (= somewhat  
> larger than 4.0). Or you can turn to the non-collinear code wienncm  
> (requires a different license and installation), where you can specify  
> and keep frozen any configuration you want.
> 
> Stefaan
> 
> 
>> Dear WIEN2k users:
>>   I am pullzed of my recent calculation results. I did a   
>> ferromagnetic state Sr2FeMoO6 calculation and a ferrimagnetic state   
>> Sr2FeMoO6 calculation to get energy difference between them, but I   
>> find the results(total energy and magnetic moments) are almost   
>> equal. I don't understand why this happens, in my opinion, the two   
>> different states should have a evident energy difference. Could spin  
>>  up electron provide spin down magnetic moment? Below is the detail:
>>
>> ferromagnetic state
>> case.inst:
>> -----------------------------------------
>> 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
>> Mo
>> Kr 3 5
>> 4, 2,2.0  N
>> 4, 2,1.0  N
>> 4,-3,2.0  N
>> 4,-3,0.0  N
>> 5,-1,1.0  N
>> 5,-1,0.0  N
>> Sr
>> Kr 1 5
>> 5,-1,1.0  N
>> 5,-1,1.0  N
>> O
>> He 3 5
>> 2,-1,1.0  N
>> 2,-1,1.0  N
>> 2, 1,1.0  N
>> 2, 1,1.0  N
>> 2,-2,1.0  N
>> 2,-2,1.0  N
>> ------------------------------------------
>> Results:
>> :ENE  : ********** TOTAL ENERGY IN Ry =       -24235.219288
>> :MMINT: MAGNETIC MOMENT IN INTERSTITIAL =    0.01427
>> :MMI001: MAGNETIC MOMENT IN SPHERE   1    =    3.77423  (Fe)
>> :MMI002: MAGNETIC MOMENT IN SPHERE   2    =   -0.25870  (Mo)
>> :MMI003: MAGNETIC MOMENT IN SPHERE   3    =   -0.00471  (Sr)
>> :MMI004: MAGNETIC MOMENT IN SPHERE   4    =    0.08151  (O)
>> :MMTOT: TOTAL MAGNETIC MOMENT IN CELL   =    4.00942
>>
>> ferrimagnetic state
>> case.inst:
>> ------------------------------
>> 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
>> Mo
>> Kr 3 5
>> 4, 2,1.0  N  <----------- spin flipped
>> 4, 2,2.0  N
>> 4,-3,0.0  N  <----------- spin flipped
>> 4,-3,2.0  N
>> 5,-1,0.0  N  <----------- spin flipped
>> 5,-1,1.0  N
>> Sr
>> Kr 1 5
>> 5,-1,1.0  N
>> 5,-1,1.0  N
>> O
>> He 3 5
>> 2,-1,1.0  N
>> 2,-1,1.0  N
>> 2, 1,1.0  N
>> 2, 1,1.0  N
>> 2,-2,1.0  N
>> 2,-2,1.0  N
>> ----------------------------------
>> Results:
>> :ENE  : ********** TOTAL ENERGY IN Ry =       -24235.219248
>> :MMINT: MAGNETIC MOMENT IN INTERSTITIAL =    0.00605
>> :MMI001: MAGNETIC MOMENT IN SPHERE   1    =    3.77188  (Fe)
>> :MMI002: MAGNETIC MOMENT IN SPHERE   2    =   -0.26145  (Mo)
>> :MMI003: MAGNETIC MOMENT IN SPHERE   3    =   -0.00538  (Sr)
>> :MMI004: MAGNETIC MOMENT IN SPHERE   4    =    0.08241  (O)
>> :MMTOT: TOTAL MAGNETIC MOMENT IN CELL   =    4.00019
>>
>>
>> Best regards,
>> Jinyun Li
> 
> 
> 
> -- 
> Stefaan Cottenier
> Instituut voor Kern- en Stralingsfysica
> K.U.Leuven
> Celestijnenlaan 200 D
> B-3001 Leuven (Belgium)
> 
> tel: + 32 16 32 71 45
> fax: + 32 16 32 79 85
> e-mail: stefaan.cottenier at fys.kuleuven.be
> 
> 
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