[CP2K-user] SCF Convergence stuck with ADMM HF?

[Vladimir Rybkin]

Dear Nick,


1) you convergence is not so bad already. At least, good enough for most 
applications.
2) You Schwarz screening is rather large. Try 10-7 and smaller. Normally, 
convergence is sensitive to the accuracy of Hartree-Fock exchange.

are you by chance running it on a Cray system?

Yours,

Vladimir

четверг, 14 мая 2020 г., 22:14:09 UTC+2 пользователь Nicholas Winner 
написал:
>
> Hello all,
>
> I have tried to perform static PBE0 calculation of diamond using the ADMM. 
> I have done many of this type of calculation before, but not for this 
> system. I have an issue where the reported "convergence" in the SCF loop is 
> unchanged for many steps. I initially tried using the DIIS minimizer and OT 
> method, but switched to 2PNT CG search to try to improve convergence. This 
> helped a tiny amount (convergence got lower, but still stuck). 
>
> I'm unclear as to what the problem is. I have attached my input and output 
> files. Note I stopped this calculation prematurely.
>
> Drawing your attention to the first inner SCF loop of the output file, I 
> can see that SCF step 19-50 all report the same convergence of (0.00000035) 
> with no change. What's more, the "total energy" in that loop is listed as -3903.4843979582 
> for all steps after 31. So it seems that the energy is extremely well 
> converged... better than the EPS_SCF 1e-7 that I listed in the input file.
>
> I'd like to know if there's any reason why this would be having such a 
> hard time converging; diamond is a large band gap material and should have 
> very good convergence with OT, especially with CG. Also, am I 
> misunderstanding hte numbers reported by the SCF steps? It seems to me the 
> total energy is very well converged to within 1e-9 the end of the first SCF 
> loop, but convergence is listed as .00000035.
>
> Any help would be appreciated.
>
> Best,
> Nick
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200515/18dbf823/attachment.htm>