[Pw_forum] convergence problem and non conventional variation in energy

[aprateek at iisermohali.ac.in]

Hi All,
I am trying to optimize lattice parameter for phosphorous sheets of 36
atoms with "P.pbe-n-kjpaw_psl.0.1.UPF" pseudopotential.
While varying lattice parameter a from 8.4 to 11.5, with
"occupations='smearing', degauss=0.02, smearing='gaussian'" keyword, we
got reverse trend in energy. I`ve attached the graph as an attachment.

When the calculations were resubmitted without "occupations='smearing',
degauss=0.02, smearing='gaussian'" keyword, some jobs got converged but
most of the jobs are not converging even after 1000 iterations.

If we plot the variation of energy w.r.t. variation in parameter a, we got
kink at 10.3.

Pl reply with your suggestions.

Prateek Ahuja
Phd(Chem), IISER-Mohali
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