[CP2K:3846] Re: Printing MO eigenvalues
MattWa... at gmail.com
Wed May 30 23:33:21 CEST 2012
The obvious suggestion is to switch to a hybrid functional. For your
current system, and extensions with a few water molecules, the cost would
be very small.
Path b is to convince Joost(I guess) that the eigenvalues of the ROKS
calculations are meaningful... - the blurb from qs_scf_post_gpw.F which
chucks up your error message is
! The issue is that one state is different from the others,
! so we certainly can't rotate all N+1 alpha states among themselves
! furthermore, alpha and beta orbitals do have the same shape,
! but not the same v_xc, therefore these seems to be no reason that
! they should have the same eigenvalues.
! So it looks like I need a convincing definition of an eigenstate in this
On Wednesday, May 30, 2012 12:14:17 PM UTC+1, Peter Tentscher wrote:
> Dear Matt,
> thanks for that hint.
> Maybe I should explain what I'm after in the end, so that The
> someone may or may not add useful information.
> I want to evaluate the shift in SOMO energy of an organic
> radical cation molecule when adding water molecules around
> it, in analogy to what Hunt&Sprik did in ChemPhysChem
> 2005, 6, 1805 ï¿½ 1808 (DOI: 10.1002/cphc.200500006)
> for closed shell inorganic ions.
> I need self-interaction correction because otherwise, the
> spin density will significantly "spill out" of the organic when
> adding water. SIC works fine with ROKS (with &OT). Whenever
> I try to use &SIC with UKS, I get <S^2> > 1 and an integrated
> spin density of 4 or so, and the resulting spin density is not
> physically meaningful. (These values are close to the ideal
> ones when not using SIC).
> You are right that the eigenvalues may not be properly
> defined for ROKS. I hope this is a systematic problem that
> wouldn't matter in my case, as I'm interested in the change
> of the eigenvalue rather than the eigenvalue itself.
> From what I've tried so far, it seems that &SIC is not
> compatible with &DIAGONALIZATION, as SCF energies just
> oscillate and do not converge to what I get with an equivalent
> &OT calculation (no matter if ROKS or UKS).
> So I'm somewhat stuck on if it's possible to get what I want.
> I'll be grateful for any type of suggestion on this matter.
> On 05/25/2012 10:46 AM, Matt W wrote:
> > Hi,
> > I think ROKS should work with diagonalization as well as OT. There's a
> > short thread "ROKS error" where Matthias implies that at least high
> > spin should be working. Whether the eigenvalues of the orbitals are
> > really properly defined I don't know.
> > Removing &OT and adding an &DIAGONALIZATION section I get energies and
> > occupations printed from &MO
> > Cheers,
> > Matt
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