Re: [QE-users] Query regarding ecutfock

[Lorenzo Bastonero]

Dear Arini,

As a final remark, this is what experience tells us, but remember that proper 
testing should be directly performed on the desired property with a desired 
accuracy.
This means that a better practice could be e.g. to test  ``ecutfock`` on phonon 
frequencies at Gamma (i.e. only displacements in UNITCELL). This already gives 
a better idea of convergence, while still not going for expensive supercells.

If you are interested in more details, I’d suggest you the following paper, 
which I found particularly instructive: 
https://www.nature.com/articles/s41524-018-0127-2 


Bests,
Lorenzo


Lorenzo Bastonero

PhD Student
U Bremen Excellence Chair,
Bremen Center for Computational Materials Science,
and MAPEX Center for Materials and Processes

University of Bremen
Faculty of Production Engineering
TAB-Building, Room 3.32
Am Fallturm 1
28359 Bremen, DE

http://www.hmi.uni-bremen.de/

> Il giorno 12 apr 2023, alle ore 14:08, Arini Kar <16i170...@iitb.ac.in> ha 
> scritto:
> 
> Dear Lorenzo,
> 
> Your suggestion was helpful. The forces on the pristine unit cell did not 
> change after reducing ecutfock to 2*ecutwfc. Thanks a lot.
> 
> 
> 
> Regards
> Arini
> 
> 
> 
> On 2023-04-12 13:26, Lorenzo Bastonero wrote:
> 
>> Dear Arini,
>>  
>> You should do some test first in the pristine unit cell structure before 
>> going forward to the supercell calculations. 
>>  
>> In principle, you could lower down even more that cutoff (and the qpoint for 
>> the fock operator as well). Usually a good threshold is ~10^-5 Ry/bohr on 
>> every atomic force component.
>>  
>> Note: this threshold is different from the one of the relax. So you should 
>> check that when changing your variables (ecutfock in this case) all your 
>> forces don't change within this threshold.
>>  
>> HTH,
>> Lorenzo 
>> 
>> Inviato da iPhone
>> 
>>> Il giorno 11 apr 2023, alle ore 20:45, Arini Kar via users 
>>>  ha scritto:
>>> 
>>> Dear users,
>>> 
>>> I am trying to run phonon calculations using phonopy. I am using norm 
>>> conserving pseudopotential. Can I use ecutfock = 2*ecutwfc instead of the 
>>> default value in the scf calculations? Would it affect the accuracy of 
>>> force calculations?
>>> 
>>> Thanking you.
>>> 
>>> Regards
>>> 
>>> Arini Kar
>>> 
>>> PhD student 
>>> 
>>> Indian Institute of Technology Bombay, India
>>> 
>>> 
>>> 
>>> ___
>>> The Quantum ESPRESSO community stands by the Ukrainian
>>> people and expresses its concerns about the devastating
>>> effects that the Russian military offensive has on their
>>> country and on the free and peaceful scientific, cultural,
>>> and economic cooperation amongst peoples
>>> ___
>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
>>> users mailing list users@lists.quantum-espresso.org
>>> https://lists.quantum-espresso.org/mailman/listinfo/users

___
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Re: [QE-users] Query regarding ecutfock

[Arini Kar via users]

Dear Lorenzo,

Your suggestion was helpful. The forces on the pristine unit cell did 
not change after reducing ecutfock to 2*ecutwfc. Thanks a lot.


Regards
Arini

On 2023-04-12 13:26, Lorenzo Bastonero wrote:


Dear Arini,

You should do some test first in the pristine unit cell structure 
before going forward to the supercell calculations.


In principle, you could lower down even more that cutoff (and the 
qpoint for the fock operator as well). Usually a good threshold is 
~10^-5 Ry/bohr on every atomic force component.


Note: this threshold is different from the one of the relax. So you 
should check that when changing your variables (ecutfock in this case) 
all your forces don't change within this threshold.


HTH,
Lorenzo

Inviato da iPhone

Il giorno 11 apr 2023, alle ore 20:45, Arini Kar via users 
 ha scritto:



Dear users,

I am trying to run phonon calculations using phonopy. I am using norm 
conserving pseudopotential. Can I use ecutfock = 2*ecutwfc instead of 
the default value in the scf calculations? Would it affect the 
accuracy of force calculations?


Thanking you.

Regards

Arini Kar

PhD student

Indian Institute of Technology Bombay, India

___
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effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
___
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[QE-users] R: Fwd: error in routine check atoms(1)

[Pietro Davide Delugas]

Hello

I haven't checked, but it looks like a simple cubic cell.  Try replacing 
ibrav=2 with ibrav=1
Pietro

Da: users  per conto di 
SPPU/05097P/2021 OYOMO BILL C 
Inviato: mercoledì 12 aprile 2023 06:48
A: users@lists.quantum-espresso.org 
Oggetto: [QE-users] Fwd: error in routine check atoms(1)



-- Forwarded message -
From: SPPU/05097P/2021 OYOMO BILL C 
mailto:billclinton...@students.tukenya.ac.ke>>
Date: Sun, Apr 9, 2023 at 8:37 PM
Subject: error in routine check atoms(1)
To: 
mailto:users-requ...@lists.quantum-espresso.org>>


Hello everyone,
I get the following error I try to run an MD calculation using a supercell 
created by xcrysden:
%%
 Error in routine check_atoms (1):
 atoms #   1 and #  25 differ by lattice vector ( 0,-1, 0) in crystal axis
 %%

 stopping ...
How do I solve the problem? Kindly look at the attached input file. Also, 
please let me know If there is any other tool for generating a supercell with 
atoms of the same unit cell arranged together rather than atoms of the same 
type of elements arranged together, which is what phonopy generates.
Thank you,
Bill C Oyomo.
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Re: [QE-users] Query regarding ecutfock

[Lorenzo Bastonero]

Dear Arini,

You should do some test first in the pristine unit cell structure before going 
forward to the supercell calculations. 

In principle, you could lower down even more that cutoff (and the qpoint for 
the fock operator as well). Usually a good threshold is ~10^-5 Ry/bohr on every 
atomic force component.

Note: this threshold is different from the one of the relax. So you should 
check that when changing your variables (ecutfock in this case) all your forces 
don’t change within this threshold.

HTH,
Lorenzo 

Inviato da iPhone

> Il giorno 11 apr 2023, alle ore 20:45, Arini Kar via users 
>  ha scritto:
> 
> 
> Dear users,
> 
> I am trying to run phonon calculations using phonopy. I am using norm 
> conserving pseudopotential. Can I use ecutfock = 2*ecutwfc instead of the 
> default value in the scf calculations? Would it affect the accuracy of force 
> calculations?
> 
> Thanking you.
> 
> Regards
> 
> Arini Kar
> 
> PhD student 
> 
> Indian Institute of Technology Bombay, India
> 
> 
> 
> ___
> The Quantum ESPRESSO community stands by the Ukrainian
> people and expresses its concerns about the devastating
> effects that the Russian military offensive has on their
> country and on the free and peaceful scientific, cultural,
> and economic cooperation amongst peoples
> ___
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users@lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
___
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
___
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list users@lists.quantum-espresso.org
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[QE-users] R: Hydrogen atom pseudopotential files with q=1.25e and q=0.75e (PBE, USPP)

[Pietro Davide Delugas]

Hello
You may find them close to the bottom of this page.
http://pseudopotentials.quantum-espresso.org/legacy_tables/original-qe-pp-library/h

They are for  LDA, but given that you are using them for the artificial 
passivation of dangling bonds, hopefully, the actual objective of your 
calculation is far enough from those bonds, and they may also do fine with 
other functionals provided that you specify the functional in input using the 
input_dft input variable.
I hope it helps; best regards
Pietro

Da: users  per conto di GOKHAN HASEKI 

Inviato: lunedì 10 aprile 2023 21:02
A: users@lists.quantum-espresso.org 
Oggetto: [QE-users] Hydrogen atom pseudopotential files with q=1.25e and 
q=0.75e (PBE, USPP)

Hi

Dear Quantum Espresso users, I would like to passivate the surface of a III-V 
nanowire with pseudo-Hydrogen atoms. So I need Hydrogen atom pseudopotential 
files with q=1.25e and q=0.75e (PBE, USPP). I've searched many pessupotential 
libraries but haven't been able to find it. your help and suggestions will 
guide me in this regard. Kind regards..
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