Re: [Wien] optimization for 225 (cubic) space group

[fatima DFT]

Thank you Dr. Tran

Yes, I took only 6x6x6 k-mesh for optimization.
I will test it further for 8x8x8, 10x10x10



On Fri, May 5, 2017 at 1:00 AM, <t...@theochem.tuwien.ac.at> wrote:

> Hi,
> If the SCF calculations were done with a value for a parameter (e.g.,
> RKmax, number of k-points or energy convergence criteria) that was
> not good enough, then this may introduce some noise such that the
> Murnaghan EOS can not fit perfectly the data and, therefore,
> leads to an optimised lattice parameter that depends on the chosen
> volumes to do the fit.
>
> In your case the fit does not seem perfect, but still reasonable
> since the variations in the lattice parameter are only at the
> third digit (at most tiny changes in the electronic properties).
>
> FT
>
> On Thursday 2017-05-04 20:34, fatima DFT wrote:
>
> Date: Thu, 4 May 2017 20:34:34
>> From: fatima DFT <fatimad...@gmail.com>
>> Reply-To: A Mailing list for WIEN2k users <w...@zeus.theochem.tuwien.ac.
>> at>
>> To: A Mailing list for WIEN2k users <Wien@zeus.theochem.tuwien.ac.at>
>> Subject: [Wien] optimization for 225 (cubic) space group
>>
>> Dear All,I finished an optimisation for 225 space group with -15% to 25%
>> volume change.
>>
>> If I plot the optimization cure for different vol parameters, I see the
>> shape of ENE vs. Vol curve changes and the optimised lattice parametes also
>> changes (at
>> third digit).
>>
>> If I plot the curve for -15 to 25% then I get the below curve
>> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/1.ps
>>
>>
>> and the optimised lattice parameters are
>>
>> 21.1924 bohr =11.2145 Ang
>>
>> For -10 to 25%,
>> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/2.ps
>>
>> 21.1984 bohr =11.2177 Ang
>>
>> For -5 to 25%
>> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/3.ps
>>
>> 21.1915 bohr =11.2140 Ang
>>
>> 0.0 to 25 %
>> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/4.ps
>>
>> 21.1917 bohr =11.2141 Ang
>>  for 5.0  to 25 %
>> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/5.ps
>> 21.2026 bohr =11.2199 Ang
>>
>>
>> My query is:
>>
>> 1. Why the optimised lattice parameters are changing if we select
>> different set of data points? The ground state should be same in all cases.
>> Is it?
>> 2.  We see from the lattice parameter the change is at third order, can
>> we take any lattice parameters (a0)? How much the third digit changes the
>> electronic
>> properties?
>>
>>
>> Warm regards
>> Fatima
>>
>>
>>
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>
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Re: [Wien] optimization for 225 (cubic) space group

[tran]

Hi,
If the SCF calculations were done with a value for a parameter (e.g.,
RKmax, number of k-points or energy convergence criteria) that was
not good enough, then this may introduce some noise such that the
Murnaghan EOS can not fit perfectly the data and, therefore,
leads to an optimised lattice parameter that depends on the chosen
volumes to do the fit.

In your case the fit does not seem perfect, but still reasonable
since the variations in the lattice parameter are only at the
third digit (at most tiny changes in the electronic properties).

FT

On Thursday 2017-05-04 20:34, fatima DFT wrote:


Date: Thu, 4 May 2017 20:34:34
From: fatima DFT <fatimad...@gmail.com>
Reply-To: A Mailing list for WIEN2k users <wien@zeus.theochem.tuwien.ac.at>
To: A Mailing list for WIEN2k users <Wien@zeus.theochem.tuwien.ac.at>
Subject: [Wien] optimization for 225 (cubic) space group

Dear All,I finished an optimisation for 225 space group with -15% to 25% volume 
change.

If I plot the optimization cure for different vol parameters, I see the shape 
of ENE vs. Vol curve changes and the optimised lattice parametes also changes 
(at
third digit).

If I plot the curve for -15 to 25% then I get the below curve
https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/1.ps


and the optimised lattice parameters are

21.1924 bohr =    11.2145 Ang

For -10 to 25%, 
https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/2.ps

21.1984 bohr =    11.2177 Ang

For -5 to 25%
https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/3.ps

21.1915 bohr =    11.2140 Ang

0.0 to 25 %
https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/4.ps

21.1917 bohr =    11.2141 Ang
 for 5.0  to 25 %
https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/5.ps
21.2026 bohr =    11.2199 Ang


My query is:

1. Why the optimised lattice parameters are changing if we select different set 
of data points? The ground state should be same in all cases. Is it?
2.  We see from the lattice parameter the change is at third order, can we take 
any lattice parameters (a0)? How much the third digit changes the electronic
properties?


Warm regards
Fatima


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Re: [Wien] optimization for 225 (cubic) space group

[Dr. K. C. Bhamu]

Dr. K. C. Bhamu
(UGC-Dr. D. S. Kothari Postdoc Fellow)
Department of Physics
Goa University, Goa-403 206
India
Mob. No.  +91-9975238952

On Fri, May 5, 2017 at 12:04 AM, fatima DFT  wrote:

> Dear All,
> I finished an optimisation for 225 space group with -15% to 25% volume
> change.
>
> If I plot the optimization cure for different vol parameters, I see the
> shape of ENE vs. Vol curve changes and the optimised lattice parametes also
> changes (at third digit).
>
> If I plot the curve for -15 to 25% then I get the below curve
> *https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/
> *
> 1.ps
>
> 
>


>
> 
>
>
> 
>
> and the optimised lattice parameters are
>
> 21.1924 bohr =11.2145 Ang
>
> For -10 to 25%,
>
> 
> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/2.ps
> 
>
> 21.1984 bohr =11.2177 Ang
>
> For -5 to 25%
>
> 
> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/3.ps
> 
>
> 21.1915 bohr =11.2140 Ang
>
> 0.0 to 25 %
>
> 
> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/4.ps
> 
>
> 21.1917 bohr =11.2141 Ang
>  for 5.0  to 25 %
> https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/5.ps
> 
> 21.2026 bohr =11.2199 Ang
>
>
> My query is:
>
> 1. Why the optimised lattice parameters are changing if we select
> different set of data points? The ground state should be same in all cases.
> Is it?
> 2.  We see from the lattice parameter the change is at third order, can we
> take any lattice parameters (a0)? How much the third digit changes the
> electronic properties?
>
>
> Warm regards
> Fatima
>
>
> ___
> 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
>
>
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[Wien] optimization for 225 (cubic) space group

[fatima DFT]

Dear All,
I finished an optimisation for 225 space group with -15% to 25% volume
change.

If I plot the optimization cure for different vol parameters, I see the
shape of ENE vs. Vol curve changes and the optimised lattice parametes also
changes (at third digit).

If I plot the curve for -15 to 25% then I get the below curve
*https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/
*1.ps




and the optimised lattice parameters are

21.1924 bohr =11.2145 Ang

For -10 to 25%,

https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/2.ps


21.1984 bohr =11.2177 Ang

For -5 to 25%

https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/3.ps


21.1915 bohr =11.2140 Ang

0.0 to 25 %

https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/4.ps


21.1917 bohr =11.2141 Ang
 for 5.0  to 25 %
https://sites.google.com/site/dftfatima5/letter/mailing-list-queries/5.ps

21.2026 bohr =11.2199 Ang


My query is:

1. Why the optimised lattice parameters are changing if we select different
set of data points? The ground state should be same in all cases. Is it?
2.  We see from the lattice parameter the change is at third order, can we
take any lattice parameters (a0)? How much the third digit changes the
electronic properties?


Warm regards
Fatima
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