[QE-users] Symmetry dependent convergence

[Paolo Giannozzi]

On Thu, Apr 7, 2022 at 3:21 PM Bidault, Xavier <xavbdlt at uic.edu> wrote:

Just my 2 cents.
>

I appreciate your 2-cent contribution, but none of your observations is
relevant to this case.

About the original post: while I think that options "noinv" and "nosym" are
a disgrace, I agree that one should obtain the same results with or without
inversion symmetry. I was able to reproduce the problem and it's definitely
a bug

Paolo


------------------------------
> *From:* users <users-bounces at lists.quantum-espresso.org> on behalf of
> Franklin T Cerasoli via users <users at lists.quantum-espresso.org>
> *Sent:* Wednesday, April 6, 2022 5:52 PM
> *To:* users at lists.quantum-espresso.org <users at lists.quantum-espresso.org>
> *Subject:* [QE-users] Symmetry dependent convergence
>
> Hello,
>
> I've been using QE for several years and recently came across an
> interesting issue when try to converge certain large systems.
>
> Attached is a link to an inputfile for a 216 atom system. With QE-6.8
> (also tested on v6.3), the structure converges only if nosym=.f. and
> noinv=.f.. There are two symmetry operations found, the identity and
> inversion.
>
> Setting nosym=.t. causes the estimated scf accuracy to thrash around in
> the hundreds of thousands of Ry, while nosym=.f. allows strong convergence
> (1e-6 Ry) within 30 iterations.
>
> Pseudopotentials are all pslibrary PBE. Below is a link to the inputfile
> and relevant parts of the scf output.
>
> I would appreciate any advice for understanding what the heck is going on
> here.
>
> -Frank Cerasoli
> UC Davis Department of Chemistry
>
> From the outputs:
>
> With nosym=.f.
>      Program PWSCF v.6.8 starts on  4Apr2022 at 16:30:24
> ...
>       2 Sym. Ops., with inversion, found
> ...
>      iteration #  1     ecut=    41.00 Ry     beta= 0.10
> ...
>      total energy              =  -84091.83957606 Ry
>      estimated scf accuracy    <       7.57588335 Ry
> ...
>      iteration #  2     ecut=    41.00 Ry     beta= 0.10
>      total energy              =  -84090.73018546 Ry
>      estimated scf accuracy    <       5.24675479 Ry
>
>      iteration #  3     ecut=    41.00 Ry     beta= 0.10
> ...
>      total energy              =  -84091.16546184 Ry
>      estimated scf accuracy    <       0.84010802 Ry
>
>
> With nosym=.t.
>      Program PWSCF v.6.8 starts on  4Apr2022 at 18: 9:20
> ...
>      No symmetry found
> ...
>      iteration #  1     ecut=    41.00 Ry     beta= 0.10
> ...
>      total energy              =  -83948.30076200 Ry
>      estimated scf accuracy    <  364559.66452101 Ry
>
>      iteration #  2     ecut=    41.00 Ry     beta= 0.10
> ...
>      total energy              =  -84392.52517827 Ry
>      estimated scf accuracy    <  209530.42525106 Ry
>
>      iteration #  3     ecut=    41.00 Ry     beta= 0.10
> ...
>      total energy              =  -85690.00953396 Ry
>      estimated scf accuracy    <  338759.15202062 Ry
>
>
> And the inputfile is here:
>
> https://drive.google.com/file/d/1jaF7drV996sg4ckxYunyHPpE79SRDdjZ/view?usp=sharing
> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1jaF7drV996sg4ckxYunyHPpE79SRDdjZ%2Fview%3Fusp%3Dsharing&data=04%7C01%7Cxavbdlt%40uic.edu%7C3441e0b59e5b441888e608da1820480b%7Ce202cd477a564baa99e3e3b71a7c77dd%7C0%7C0%7C637848824348798187%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=boGqNRGVk6%2FJ0GVhqmBt0e2dZh9yQwLom3%2FdG1KPPBU%3D&reserved=0>
>
> _______________________________________________
> 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 at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users



-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20220407/ad5fc2b4/attachment.html>