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pw.x and PBE0

Posted: Tue Mar 31, 2026 4:05 am
by sunxl
Dear all,

When I was using QE to calculate the pbe0 scf, the calculation converged but then got stuck at this step. There was no new output for a long time. Could you please tell me if there is anything wrong with my settings? The specific settings are provided in the attachment.
the Fermi energy is -3.2700 ev

! total energy = -781.67333230 Ry
estimated scf accuracy < 0.00000006 Ry
smearing contrib. (-TS) = -0.00182922 Ry
internal energy E=F+TS = -781.67150308 Ry

convergence has been achieved in 9 iterations

Using ACE for calculation of exact exchange

EXX grid: 765195 G-vectors FFT dimensions: ( 225, 225, 32)
ACE projected onto 250 (nbndproj) and applied to 250 (nbnd) bands

Re: pw.x and PBE0

Posted: Tue Mar 31, 2026 8:14 am
by Daniele Varsano
Dear Sunxl,

Hybrid calculations are much more demanding than calculation with local/semilocal functional and implies two nested loops.
it seems to be stacked at the beginning of the exact exchange calculation. This step is computational intensive so it is possible you have memory issue or need more resource to run the calculation in reasonable time. I suggest you to try to run the calculation using more resources , or anyway ask advice to the QE mailing list.

Moreover you can possibly reduce the nqx3 value, but you need then to check the convergence.

Best,
Daniele