Relaxation not stopping when EDIFFG is reached.

Queries about input and output files, running specific calculations, etc.


Moderators: Global Moderator, Moderator

Locked
Message
Author
jonathan_schmidt
Newbie
Newbie
Posts: 9
Joined: Sat Jun 10, 2023 1:44 pm

Relaxation not stopping when EDIFFG is reached.

#1 Post by jonathan_schmidt » Tue Aug 22, 2023 4:18 pm

I was running the attached relaxation and using grep -A 23 TOTAL-FORCE OUTCAR it seemed that the forces were already quite a bit smaller than EDIFFG = -0.0001 without the relaxation stopping.
Anything I can do to change this or any setting is wrong? It's seems to just be wasting computing time.
thank you so much.

e.g.
POSITION TOTAL-FORCE (eV/Angst)
-----------------------------------------------------------------------------------
0.00000 -0.00000 1.95875 -0.000000 0.000000 0.000000
2.73442 2.73442 1.95875 -0.000000 0.000000 -0.000000
2.73442 2.73442 5.87624 -0.000000 0.000000 -0.000000
0.00000 -0.00000 5.87624 -0.000000 0.000000 -0.000000
2.73442 0.00000 3.91750 -0.000000 -0.000000 0.000000
0.00000 2.73442 3.91750 -0.000000 0.000000 0.000000
0.00000 2.73442 7.83499 -0.000000 -0.000000 0.000000
2.73442 0.00000 7.83499 -0.000000 0.000000 0.000000
2.73442 0.00000 1.95875 -0.000000 0.000000 -0.000000
0.00000 2.73442 1.95875 -0.000000 0.000000 0.000000
3.90368 3.90368 0.00000 0.000002 0.000002 0.000000
4.29958 4.29958 3.91749 -0.000002 -0.000002 0.000000
1.56516 3.90368 3.91749 -0.000002 0.000002 0.000000
1.16926 4.29958 0.00000 0.000002 -0.000002 0.000000
0.00000 2.73442 5.87624 -0.000000 0.000000 -0.000000
2.73442 0.00000 5.87624 -0.000000 0.000000 0.000000
1.16926 1.16926 3.91749 0.000002 0.000002 0.000000
1.56516 1.56516 0.00000 -0.000002 -0.000002 0.000000
4.29958 1.16926 0.00000 -0.000002 0.000002 0.000000
3.90368 1.56516 3.91749 0.000002 -0.000002 0.000000
-----------------------------------------------------------------------------------
total drift: 0.000000 0.000000 0.000000
You do not have the required permissions to view the files attached to this post.

manuel_engel1
Global Moderator
Global Moderator
Posts: 126
Joined: Mon May 08, 2023 4:08 pm

Re: Relaxation not stopping when EDIFFG is reached.

#2 Post by manuel_engel1 » Thu Aug 24, 2023 9:25 am

The settings are correct. There is nothing wrong with your calculation per se. However, the EDIFFG setting is a bit more complicated than the current VASP wiki entry would lead you to believe. For ISIF=3, the cell shape/volume is allowed to change. In this case, the break condition specified by EDIFFG also includes the stress tensor, not just the forces. This is not properly documented online and we are sorry for the confusion. We are currently exploring possibilities of how to improve the situation.
Manuel
VASP developer

jonathan_schmidt
Newbie
Newbie
Posts: 9
Joined: Sat Jun 10, 2023 1:44 pm

Re: Relaxation not stopping when EDIFFG is reached.

#3 Post by jonathan_schmidt » Tue Aug 29, 2023 3:20 pm

Thank you very much for the reply, do you have some stopping equation in terms of stress components and EDIFFG that you can share.

Locked