Re: [Wien] spin configuration for charge state

2016-05-12 Thread Peter Blaha 

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 2.402.58
Atom   2 equiv  1 Co Bond-Valence Sum 3.033.20
Atom   3 equiv  1 O O1   Bond-Valence Sum 2.252.39
Atom   4 equiv  1 O O2   Bond-Valence Sum 1.671.78

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  0.0  0.0  0.0 -0.04204
  0.0  0.93434  0.0  0.0  0.0
  0.0  0.0  0.91726  0.0  0.0
  0.0  0.0  0.0  0.93434  0.0
 -0.04204  0.0  0.0  0.0  0.89437
Total spin moment: 4.57467
For Co dn spin
  0.34200  0.0  0.0  0.0 -0.05202
  0.0  0.33947  0.0  0.0  0.0
  0.0  0.0  0.34654  0.0  0.0
  0.0  0.0  0.0  0.33947  0.0
 -0.05202  0.0  0.0  0.0  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 > wrote:

Dear Prof. Peter
Thank you for your kind reply..

The Density matrix for Co up spin is..
  0.84607  0.0  0.0  0.0 -0.08661
  0.0  0.92206  0.0  0.0  0.0
  0.0  0.0  0.59673  0.0  0.0
  0.0  0.0  0.0  0.92206  0.0
 -0.08661  0.0  0.0  0.0  0.84607
Total electrons: 4.13298
and Density matrix for Co dn spin is:
  0.20583  0.0  0.0  0.0  0.06263
  0.0  0.80064  0.0  0.0  0.0
  0.0  0.0  0.25923  0.0  0.0
  0.0  0.0  0.0  0.80064  0.0
  0.06263  0.0  0.0  0.0  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 > 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
> 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

Re: [Wien] spin configuration for charge state

2016-05-12 Thread Laurence Marks 
The first BVS number is for the lattice you used, the second is an
approximate estimate for an expanded lattice with the typical PBE
expansion. You can/should put into a file ".latcalib" (note the "." at the
front) the linear expansion/contraction for the DFT optimized volume.

The numbers you have are a bit odd, particularly the Sr is rather high. Did
you take the positions from some report of SrCoO2.5 or are you just
calculating the metastable SrCoO3? If a phase is metastable (or unstable)
you cannot expect it to yield "simple" results such as a Co4+ valence. The
Sr-Co-O family is quite complex.

On Thu, May 12, 2016 at 4:44 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 2.402.58
> Atom   2 equiv  1 Co Bond-Valence Sum 3.033.20
> Atom   3 equiv  1 O O1   Bond-Valence Sum 2.252.39
> Atom   4 equiv  1 O O2   Bond-Valence Sum 1.671.78
>
> 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  0.0  0.0  0.0 -0.04204
>  0.0  0.93434  0.0  0.0  0.0
>  0.0  0.0  0.91726  0.0  0.0
>  0.0  0.0  0.0  0.93434  0.0
> -0.04204  0.0  0.0  0.0  0.89437
> Total spin moment: 4.57467
> For Co dn spin
>  0.34200  0.0  0.0  0.0 -0.05202
>  0.0  0.33947  0.0  0.0  0.0
>  0.0  0.0  0.34654  0.0  0.0
>  0.0  0.0  0.0  0.33947  0.0
> -0.05202  0.0  0.0  0.0  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 
> wrote:
>
>> Dear Prof. Peter
>> Thank you for your kind reply..
>>
>> The Density matrix for Co up spin is..
>>  0.84607  0.0  0.0  0.0 -0.08661
>>  0.0  0.92206  0.0  0.0  0.0
>>  0.0  0.0  0.59673  0.0  0.0
>>  0.0  0.0  0.0  0.92206  0.0
>> -0.08661  0.0  0.0  0.0  0.84607
>> Total electrons: 4.13298
>>
>> and Density matrix for Co dn spin is:
>>  0.20583  0.0  0.0  0.0  0.06263
>>  0.0  0.80064  0.0  0.0  0.0
>>  0.0  0.0  0.25923  0.0  0.0
>>  0.0  0.0  0.0  0.80064  0.0
>>  0.06263  0.0  0.0  0.0  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 
>> 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 
>>> 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

Re: [Wien] cohesive energy

2016-05-12 Thread Laurence Marks 
To obtain reasonable results you have to be fully consistent with
everything, e.g. RMT, RKMAX, U's etc.

On Thu, May 12, 2016 at 10:37 AM, Zsolt Rak  wrote:

> ​​
> Dear users,
>
> I am calculating the cohesive energy of a series of transition metal (TM)
> oxides and I have the following questions: because the energy of the TMO is
> calculated within the LDA+U framework should I use the same LDA+U for the
> free atoms? Does it make sense to subtract LDA+U/GGA+U energies of oxides
> from LDA/GGA energies of free atoms? Does it make sense to use LDA+U/GGA+U
> for free atom calculations?
> Thanks,
> Zsolt
>



-- 
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody
else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu
Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent
Co-Editor, Acta Cryst A
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[Wien] cohesive energy

2016-05-12 Thread Zsolt Rak 
​​
Dear users,

I am calculating the cohesive energy of a series of transition metal (TM)
oxides and I have the following questions: because the energy of the TMO is
calculated within the LDA+U framework should I use the same LDA+U for the
free atoms? Does it make sense to subtract LDA+U/GGA+U energies of oxides
from LDA/GGA energies of free atoms? Does it make sense to use LDA+U/GGA+U
for free atom calculations?
Thanks,
Zsolt
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Re: [Wien] spin configuration for charge state

2016-05-12 Thread Komal Bapna 
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 2.402.58
Atom   2 equiv  1 Co Bond-Valence Sum 3.033.20
Atom   3 equiv  1 O O1   Bond-Valence Sum 2.252.39
Atom   4 equiv  1 O O2   Bond-Valence Sum 1.671.78

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  0.0  0.0  0.0 -0.04204
 0.0  0.93434  0.0  0.0  0.0
 0.0  0.0  0.91726  0.0  0.0
 0.0  0.0  0.0  0.93434  0.0
-0.04204  0.0  0.0  0.0  0.89437
Total spin moment: 4.57467
For Co dn spin
 0.34200  0.0  0.0  0.0 -0.05202
 0.0  0.33947  0.0  0.0  0.0
 0.0  0.0  0.34654  0.0  0.0
 0.0  0.0  0.0  0.33947  0.0
-0.05202  0.0  0.0  0.0  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  wrote:

> Dear Prof. Peter
> Thank you for your kind reply..
>
> The Density matrix for Co up spin is..
>  0.84607  0.0  0.0  0.0 -0.08661
>  0.0  0.92206  0.0  0.0  0.0
>  0.0  0.0  0.59673  0.0  0.0
>  0.0  0.0  0.0  0.92206  0.0
> -0.08661  0.0  0.0  0.0  0.84607
> Total electrons: 4.13298
>
> and Density matrix for Co dn spin is:
>  0.20583  0.0  0.0  0.0  0.06263
>  0.0  0.80064  0.0  0.0  0.0
>  0.0  0.0  0.25923  0.0  0.0
>  0.0  0.0  0.0  0.80064  0.0
>  0.06263  0.0  0.0  0.0  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  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 
>> 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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