[Wien] spin configuration for charge state
Peter Blaha
pblaha at theochem.tuwien.ac.at
Thu May 12 18:18:11 CEST 2016
Did you do a structure optimization (runsp -min ) ???
This is probably mandatory !
> Total energy is 516 meV greater than the previous case.
You mean more negative (or the absolute value is "greater") ?
We usually say the total energy of a more stable configuration is more
negative ....
The 5 mB of Co4+ are again an idealization of a purely ionic model. It
does not exist in nature.
On 05/12/2016 11:44 AM, Komal Bapna wrote:
> Dear Prof. Peter and Laurence,
>
> I am really thankful for your valuable suggestions.
>
> /Prof. Laurence::/
> /
> /
> These are the bond-valence sums, I am getting
> Atom 1 equiv 1 Sr Bond-Valence Sum 2.40 2.58
> Atom 2 equiv 1 Co Bond-Valence Sum 3.03 3.20
> Atom 3 equiv 1 O O1 Bond-Valence Sum 2.25 2.39
> Atom 4 equiv 1 O O2 Bond-Valence Sum 1.67 1.78
>
> Please tell the two values in each line. Can I now say that these are
> the valence state for respective atom. If it is so, why for Co it is not
> 4!!!!
>
>
> /Prof. Peter:: /
> /
> /
> I tried to stabilize a "high-spin" state for Co by changing the 0.8 on
> spin-dn to 0.2, and the 0.59 to 0.9 in spin-up.
> For Co up spin
> 0.89437 0.00000 0.00000 0.00000 -0.04204
> 0.00000 0.93434 0.00000 0.00000 0.00000
> 0.00000 0.00000 0.91726 0.00000 0.00000
> 0.00000 0.00000 0.00000 0.93434 0.00000
> -0.04204 0.00000 0.00000 0.00000 0.89437
> Total spin moment: 4.57467
> For Co dn spin
> 0.34200 0.00000 0.00000 0.00000 -0.05202
> 0.00000 0.33947 0.00000 0.00000 0.00000
> 0.00000 0.00000 0.34654 0.00000 0.00000
> 0.00000 0.00000 0.00000 0.33947 0.00000
> -0.05202 0.00000 0.00000 0.00000 0.34200
> Total spin moment: 1.70947
>
> Total energy is 516 meV greater than the previous case.
> SPIN MAGNETIC MOMENTS OF MIXED CHARGE DENSITY
> INTERSTITIAL = 0.14578
> Sr = 0.00800
> Co = 2.89880
> O1 = 0.23087
> O2 = 0.17575
> total moment in the CELL = 3.87383
>
> Looking at the moments, can I say Co is in high spin state, as the
> moment is still low than its actual theoretical high spin moment (~5 muB).
>
> Thanks and Regards
>
> On Tue, May 10, 2016 at 5:24 PM, Komal Bapna <komal.bapna at gmail.com
> <mailto:komal.bapna at gmail.com>> wrote:
>
> Dear Prof. Peter
> Thank you for your kind reply..
>
> The Density matrix for Co up spin is..
> 0.84607 0.00000 0.00000 0.00000 -0.08661
> 0.00000 0.92206 0.00000 0.00000 0.00000
> 0.00000 0.00000 0.59673 0.00000 0.00000
> 0.00000 0.00000 0.00000 0.92206 0.00000
> -0.08661 0.00000 0.00000 0.00000 0.84607
> Total electrons: 4.13298
> and Density matrix for Co dn spin is:
> 0.20583 0.00000 0.00000 0.00000 0.06263
> 0.00000 0.80064 0.00000 0.00000 0.00000
> 0.00000 0.00000 0.25923 0.00000 0.00000
> 0.00000 0.00000 0.00000 0.80064 0.00000
> 0.06263 0.00000 0.00000 0.00000 0.20583
> Total electrons: 2.27217
>
> This gives me the net spin moment of 1.86 muB on Co.
> I understood by changing the occupancies we can change the spin
> state. Still I am confused whether I can use these occupation
> numbers of electrons in the respective orbitals to find the spin
> state of Co.Here, total number of electrons is 6.4, 1.4 electrons
> higher than the expected value for Co4+ ion. I may consider the
> extra electrons due to the bonding of Co-O bonds. But, I am really
> unable to calculate the spin state from the present configuration.
> Please suggest how to calculate spin state for the given
> configuration, so that I can modify further.
>
> Thanks and Regards
>
> On Mon, May 9, 2016 at 3:59 PM, Komal Bapna <komal.bapna at gmail.com
> <mailto:komal.bapna at gmail.com>> wrote:
>
> Sir,
>
> Its true that we can not generate "ionic" electron density with lstart/dstart. When I tried to modify .inst file according to the Co4+ ionic state, it showed error.
>
> My query is that how can we generate spin state configuration for such an ionic state, it spin states for Co and Co4+ are different and accordingly the magnetic moments.
>
>
> Please suggest.
>
>
> Thanks
>
>
> On Fri, May 6, 2016 at 3:18 PM, Komal Bapna
> <komal.bapna at gmail.com <mailto:komal.bapna at gmail.com>> wrote:
>
> Dear Wien users
>
> I am working on Sr2CoO4. Here I wanted to study the system with different spin state configuration of Co4+, which is known to be valence state of Co in this system. I could understand how to create:
> (a) High-spin configuration
> (b) Intermediate spin configuration
> (c) Low-spin configuration
> for the given Co atoms in the .inst file as
>
> Co
> Ar 3
> 3, 2,2.0 N
> 3, 2,2.0 N
> 3,-3,3.0 N
> 3,-3,0.0 N
> 4,-1,1.0 N
> 4,-1,1.0 N (for HS state)
> and
> Co
> Ar 3
> 3, 2,2.0 N
> 3, 2,2.0 N
> 3,-3,2.0 N
> 3,-3,1.0 N
> 4,-1,1.0 N
> 4,-1,1.0 N (for IS state)
>
>
> But my query is that .inst file takes Co as neutral atom (9
> electrons:3d74s2) and accordingly its spin state. As if Co were in 4+ state, I would have 5 electrons in 3d state (3d54s0) rather 9 electrons as is revealed from .inst file now.
>
> Please suggest me how to give spin state for Co4+ for this system.
>
>
> Thanks
>
>
>
> --
> *Komal*
>
>
>
>
> --
> *Komal*
>
>
>
>
> --
> *Komal*
>
>
>
>
> --
> *Komal*
>
>
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--
P.Blaha
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