[QE-users] NEB calculation no symmetry found

[Offermans Willem]

Dear Paolo Giannozzi and Quantum Espresso friends,

I thank you 1001 times for your remark that the neb.x code deals with symmetry in a most expected way.
Combined with the information about the pw_1.in file and the diff program, I was able to detect my mistake.

Unfortunately I had changed the unit cell vectors a bit by mistake. This led to a lost of the symmetry.

I’m sorry for the noise I created, but it was really a puzzle for me.

Thank you for your effort and attention.


Met vriendelijke groeten,
Mit freundlichen Grüßen,
With kind regards,


Willem Offermans
Researcher Electrocatalysis SCT
VITO NV | Boeretang 200 | 2400 Mol
Phone:+32(0)14335263 Mobile:+32(0)492182073

Willem.Offermans at Vito.be<mailto:Willem.Offermans at Vito.be>

[cid:982BA063-B96A-4A1B-89AB-5A01CA9FC70D at vito.local]

On 14 Feb 2019, at 10:04, Giovanni Cantele <giovanni.cantele at spin.cnr.it<mailto:giovanni.cantele at spin.cnr.it>> wrote:

from PW/src/symm_base.f90 :

  ! ... these are acceptance criteria
  !
  REAL(DP), PARAMETER :: eps1 = 1.0d-6, eps2 = 1.0d-5


I guess you can change those values and recompile the code to force it to use a certain tolerance
Giovanni


On 14 Feb 2019, at 09:58, Fabrizio Cossu <fabrizio.cossu at apctp.org<mailto:fabrizio.cossu at apctp.org>> wrote:



On Thu, 14 Feb 2019 at 17:37, Paolo Giannozzi <p.giannozzi at gmail.com<mailto:p.giannozzi at gmail.com>> wrote:
On Thu, Feb 14, 2019 at 8:34 AM Offermans Willem <willem.offermans at vito.be<mailto:willem.offermans at vito.be>> wrote:

So neb.x is able to detect symmetry. Only in my particular case, it is not able to and I wonder why.

the reason has been explained no less than 1001 times: if the code does not find a symmetry, it's not there, according to the criteria implemented in the code.

Paolo

A DFT code should recognise symmetry operations within a certain tolerance given the coordinates of the atoms. A quick search ("symmetry", "tolerance") in the pw.x input options does not return any result for a tunable parameter. What is the default value for the tolerance, and what should I do if I had to define a certain tolerance?
Thank you,
Fabrizio

--
Fabrizio Cossu
postdoctoral fellow at APCTP (Asia Pacific Center for Theoretical Physics),
Hogil Kim Memorial Building #501
POSTECH, 67 Cheongam-Ro, Nam-Gu,
Pohang-si, Gyeongsangbuk-do,
790-784 (37673), Republic of Korea

                       |
  .----. .----. .----. |----  .----.   ===========================
  ,----| |    | |      |      |    |   http://www.apctp.org/?JrgId=16
  `----^ |----' `----' `----' |----'   ===========================
         |                    |

_______________________________________________
users mailing list
users at lists.quantum-espresso.org<mailto:users at lists.quantum-espresso.org>
https://lists.quantum-espresso.org/mailman/listinfo/users

--

Giovanni Cantele, PhD

CNR-SPIN
c/o Dipartimento di Fisica
Universita' di Napoli "Federico II"
Complesso Universitario M. S. Angelo - Ed. 6
Via Cintia, I-80126, Napoli, Italy

e-mail: giovanni.cantele at spin.cnr.it<mailto:giovanni.cantele at spin.cnr.it>
            gcantele at gmail.com<mailto:gcantele at gmail.com>
Phone: +39 081 676910
Skype contact: giocan74
Web page: https://sites.google.com/view/giovanni-cantele

_______________________________________________
users mailing list
users at lists.quantum-espresso.org<mailto:users at lists.quantum-espresso.org>
https://lists.quantum-espresso.org/mailman/listinfo/users

Indien u VITO Mol bezoekt, hou aub er dan rekening mee dat de hoofdingang voortaan enkel bereikbaar is vanuit de richting Dessel-Retie, niet vanuit richting Mol, zie vito.be/route.<http://www.vito.be/route>
If you plan to visit VITO at Mol, then please note that the main entrance can only be reached coming from Dessel-Retie and no longer coming from Mol, see vito.be/en/contact/locations.<http://www.vito.be/en/contact/locations>
VITO Disclaimer: http://www.vito.be/e-maildisclaimer
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20190214/d898d346/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: vito.jpg
Type: image/jpeg
Size: 15232 bytes
Desc: vito.jpg
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20190214/d898d346/attachment.jpg>