date:20160510

Re: [Wien] spin configuration for charge state

2016-05-10 Thread Laurence Marks

To clarify one point, you have to be careful about the meaning of Co"4+".

The "4+" is a formal valence, which is quite well reproduced by the
bond-valence sums (BVS), e.g. do "x nn ; grep Bond *tnn". It is also what
people use when they refer to different atom states as observed by XPS,
EELS etc.

This is different from the actual charge within the muffin tins (look at
the relevant :CTO), the d-electron density from the density matrix, the
spin from the magnetic moment, the Bader charge and the dynamic
polarization charge (Born charge).

On Tue, May 10, 2016 at 7:33 AM, Peter Blaha 
wrote:

> a) I don't think that you will ever get a 3d-occupation which is in
> agreement with the "formal" valence (therfore this is called "formal").
> This starts even for a very ionic TiO2, where formally the 3d electrons
> of Ti4+ should all be empty, but are not in reality.
>
> b) Try 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.
> After modification of the dmatup/dn files, run:
>
> x orb -up/dn
> runsp -orbc
> save constraint_high_spin
> runsp -orb
>
> and check the final results, if the spin (charge) state has changed.
> Also compare the total energies of the present and the new solution.
>
>
> On 05/10/2016 01:54 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*
> >
> >
> > ___
> > Wien mailing list
> > Wien@zeus.theochem.tuwien.ac.at
> >

Re: [Wien] spin configuration for charge state

2016-05-10 Thread Peter Blaha

a) I don't think that you will ever get a 3d-occupation which is in 
agreement with the "formal" valence (therfore this is called "formal").
This starts even for a very ionic TiO2, where formally the 3d electrons 
of Ti4+ should all be empty, but are not in reality.


b) Try 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.

After modification of the dmatup/dn files, run:

x orb -up/dn
runsp -orbc
save constraint_high_spin
runsp -orb

and check the final results, if the spin (charge) state has changed.
Also compare the total energies of the present and the new solution.


On 05/10/2016 01:54 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*


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--

  P.Blaha
--
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
Email: bl...@theochem.tuwien.ac.atWIEN2k: http://www.wien2k.at
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Re: [Wien] spin configuration for charge state

2016-05-10 Thread Komal Bapna

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*
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Re: [Wien] Ghost band error in mbj calculation

2016-05-10 Thread shamik chakrabarti

Dear Tran & wien2k users,

After running almost 140 iterations when I
switch the mixing parameter from 0.05 (initial mixing param.) to 0.2, (as
the charge convergence was oscillating within 0.01 for almost 30 odd
iterations), ghost band appears at the same cycle (at which I have changed
the mixing grid).

Is is that the ghost band appeared due to a sudden change in mixing
parameter? Should I wait till the cc goes down to at least 0.001 before I
change the mixing grid such that the calculation do not stop at some local
minima?

Any response is eagerly awaited.

Thanks in advance,

with regards,

On Tue, Apr 5, 2016 at 9:43 AM, shamik chakrabarti 
wrote:

> Thanks Tran. Its working.
>
> On Fri, Apr 1, 2016 at 9:16 PM,  wrote:
>
>> Hi,
>>
>> you can try to start the mBJ calculation with the electron density
>> from the GGA+U calculation (before executing runsp_lapw for mBJ,
>> copy case.clm/sum/up/dn from the GGA+U calculations). Maybe the
>> QTL-B value at the 1st iteration is smaller such that the
>> calculation does not stop. This can happen that large QTL-B values
>> occur only at the 1st or two first iterations and then disappear.
>>
>> F. Tran
>>
>> On Friday 2016-04-01 15:34, shamik chakrabarti wrote:
>>
>> Date: Fri, 1 Apr 2016 15:34:17
>>> From: shamik chakrabarti 
>>> Reply-To: A Mailing list for WIEN2k users <
>>> wien@zeus.theochem.tuwien.ac.at>
>>> To: A Mailing list for WIEN2k users 
>>> Subject: [Wien] Ghost band error in mbj calculation
>>>
>>>
>>> Dear wien2k users,
>>>  I am trying to run an mbj calculation for a
>>> spinel
>>> compound. It shows ghost-band error in its first cycle. However, either
>>> in
>>> GGA or GGA+U the same struct file showed no error and calculation
>>> converge
>>> smoothly. I have check the case.scf2 file & it shows,
>>>
>>> :WARN : QTL-B value eq.  19.18 in Band of energy  -1.72960  ATOM=   38
>>>  L=
>>>  1
>>>
>>> Any response in this regard is greatly awaited.
>>>
>>> Thanks in advance.
>>>
>>> with regards,
>>>
>>> --
>>> Dr. Shamik Chakrabarti
>>> Research Associate
>>> Electroceramics Lab
>>> Dept. of Metallurgical & Materials Engineering
>>> IIT Kharagpur
>>> Kharagpur 721302
>>> INDIA
>>>
>>>
>> ___
>> Wien mailing list
>> Wien@zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>> SEARCH the MAILING-LIST at:
>> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>>
>>
>
>
> --
> Dr. Shamik Chakrabarti
> Research Associate
> Electroceramics Lab
> Dept. of Metallurgical & Materials Engineering
> IIT Kharagpur
> Kharagpur 721302
> INDIA
>



-- 
Dr. Shamik Chakrabarti
Research Associate
Electroceramics Lab
Dept. of Metallurgical & Materials Engineering
IIT Kharagpur
Kharagpur 721302
INDIA
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Re: [Wien] spin configuration for charge state

Re: [Wien] spin configuration for charge state

Re: [Wien] spin configuration for charge state

Re: [Wien] Ghost band error in mbj calculation

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