Hi all,

I was wondering if anyone has any general advice for getting quasi Fermi level calculations to run without crashing? I’ve done some calculations for various systems, usually geometry + cell relaxation with fixed nqfd, around 0.1-0.5 e/f.u. In general I have a large plane wave cutoff (~1000 eV), a fairly dense k-grid (8-12 in each direction). The smearing is something I’ve been treating as a physical parameter and fixing in calculations (it makes quite a big difference in the results), but is usually a few mHa.

My calculations always eventually crash, saying that a new Fermi level couldn’t be found in some number of bisections. I modified the code to increase the max number of bisections from 50, to 1000, but it doesn’t make any difference. Also I have tried increasing the number of bands, up to several hundred (for < 50 valence bands), and it still always eventually crashes.

I was wondering if anyone else had similar experiences, and any general advice for getting these calculations to run without crashing? It seems to happen regardless of the material.

Thanks,

Daniel Bennett