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

[Jan Elsner]

Dear all, 

 

I'm running a single point calculation on a positively charged rubrene (C42H
28) 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


*EDIT:*

I thought I should also add, when I try to use Fermi-Dirac smearing, I get 
the following errors:  "WARNING in qs_mo_occupation.F:118 :: Fermi-Dirac 
smearing includes the first MO" and "WARNING in qs_mo_occupation.F:122 :: 
Fermi-Dirac smearing includes the last MO => Add more MOs for proper 
smearing. "


This occurs even when I use a tiny Electronic Temperature (0.1 K) and 100 
added MOs for each spin channel (files attached).

 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200619/2665cc42/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dimer-pbe-50hfx.inp
Type: chemical/x-gamess-input
Size: 7941 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200619/2665cc42/attachment.inp>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dimer-pbe-50hfx.out
Type: application/octet-stream
Size: 31878 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200619/2665cc42/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: RUB_P_PBE-GTH_DZVP-GTH_single_point-RESTART.wfn
Type: application/octet-stream
Size: 4307276 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200619/2665cc42/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dimer-pbe-50hfx-smearing.inp
Type: chemical/x-gamess-input
Size: 8044 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200619/2665cc42/attachment-0001.inp>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dimer-pbe-50hfx-smearing.out
Type: application/octet-stream
Size: 13868 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200619/2665cc42/attachment-0002.obj>