[gpaw-users] NEB calculations convergence issues

[Manuel Šaric]

Dear all,

I am trying to simulate the process of cleaving the C-S bond of CH3SH by hydrogen on the surface of CoMoS (MoS2 promoted by Co). The problem that I run into is that the forces never converge, they jump between a couple of energies in circles. I also notice that after a certain time the calculation starts writing the same energy at the same time with the same forces about 10 times in a row to the logfile. If I check the trajectory file for each image they all reach a point where the energy doesn't change and the atoms aren't being moved but the calculation is still running.

I have attached the logfile, the input file, the initial and final configuration as well as a trajectory with the starting path.

This is done with lcao but once upon a time I ran into the same problem using fd mode or PW with different molecules containing sulfur.
I have also tried using different optimizers (BFGS, FIRE, and some SciPy optimizers), not much changes.
I encounter the same problem if I try to simulate the dissociation of H2 into H adsorbed on the edge sulfurs of the surface we have here.

Let me know if you have any advice.

Thanks in advance,

Manuel
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