[CP2K-user] SCF convergence using PBE+50%HFX on +ve dimer

[Jan Elsner]

I solved this by decreasing EPS_PGF_ORB to 1.0E-40 and removing 
EPS_FILTER_MATRIX. 

Jan




On Friday, June 19, 2020 at 12:08:08 PM UTC+1, Jan Elsner wrote:
>
> Dear all, 
>
>  
>
> I'm running a single point calculation on a positively charged rubrene (C
> 42H28) dimer (spin polarized calculation) using PBE+50%HFX, restarting 
> from a converged PBE wavefunction. Unfortunately the SCF does not converge 
> after 350 steps. The "convergence" value jumps to huge values at SCF step 2 
> ("convergence" at SCF step1 = *3.3*, "convergence" at SCF step2 = *12281*) 
> and at longer times (around SCF step 150 onwards), it shows oscillatory 
> behaviour. The behaviour is the same if I use RESTART ATOMIC. 
>
>  
>
> I note:
>
>    - The SCF also doesn't converge for the neutral dimer
>    - The SCF *does converges *for both the neutral and cationic *single 
>    rubrene molecule*
>    - For the dimer, I have tried a number of settings: different mixing 
>    schemes (BROYDEN, DIRECT_P_MIXING), diagonalization and OT method, larger 
>    CUTOFF, smaller EPS_SCHWARZ
>    - I also can't converge the SCF using PBE0, where I observe similar 
>    behaviour 
>
> I attach the relevant files. Any help would be much appreciated. 
>
>  
>
> Best,
>
>  
>
> Jan
>
>  
>
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