[ase-users] NEB code

[Alaithan, Zainab]

Thank you for the explanation. I am also facing convergence problem with my reaction as you can see in the log file. I am not sure what could be the cause for the optimizer to behave in this way. The fmax was going down initially as can be seen in neb_1.log until it reached 0.4 in neb_2.log and then started to go up again. On the other hand, the energy is going down consistently but slowly where the forces start to increase.


It seems to me that the energy surface at this region is rugged but the curvature is flatter. I am not sure if there is a remedy for this, or whether there are alternative convergence criteria or tests that I can use to locate the transition state geometry with more accuracy.


Regards,

________________________________
From: ase-users-bounces at listserv.fysik.dtu.dk <ase-users-bounces at listserv.fysik.dtu.dk> on behalf of Peterson, Andrew via ase-users <ase-users at listserv.fysik.dtu.dk>
Sent: 23 August 2019 20:42:53
To: ase-users at listserv.fysik.dtu.dk <ase-users at listserv.fysik.dtu.dk>
Subject: Re: [ase-users] NEB code


You probably saw the line<https://gitlab.com/ase/ase/blob/master/ase/neb.py#L315> f = forces[i - 1], and then f is modified. That first line returns a “view” of the original array, so when f is modified so is the original forces array. It's just a numpy way of dealing with slices.


On Tue, Aug 20, 2019 at 11:37 AM Alaithan, Zainab via ase-users <ase-users at listserv.fysik.dtu.dk<mailto:ase-users at listserv.fysik.dtu.dk>> wrote:

I am examining NEB code because I am facing some convergence problems when I increase the number of images from 3. I noticed that NEB get.forces method returns the real forces instead of the modified forces.


The modified forces are calculated as 'f'
but the method returns 'forces' rather than 'f'


am I missing something?


Thank you,


Regards,

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Andrew Peterson
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