[Wien] about a warning at case.SCF

[george bush]

many thanks for Pro. Blaha, actually before I received
your valuable email, I have tried tyhe Gauss mode. it
is really OK. anyway, thanks a lot. but another
question: when I set R*K = 24, I found the Gmax should
be no more than 25,why?
another question why use only 1 k point to calculate
the total energy.

RUBBI

--- Peter Blaha <pblaha at zeus.theochem.tuwien.ac.at>
wrote:
> > while I was calculating the total energy of single
> > nitrogen atom, what I did completely was based on
> the
> > instruction of Pro.Blaha: FCC, a=b=c=20bohr, and
> 1k
> > point. I used the RK = 8; lmax = 12. but it is
> still
> > not easy to converge. and I found a warning at the
> > case.scf which red as:
> > :WARN : RESULT OF INTEGRATION:    1.00000; SHOULD
> BE:
> >   2.50000.
> > who can tell me what does it mean? and how to
> improve.
> 
> In atoms one has very often degenerate eigenvalues,
> which are however,
> only paritally occupied. Thus it happens often that
> the occupation
> of these formally degenerate states cannot be
> determined properly by the
> tetrahedron method.
> 
> Used a broadening method (GAUSS or TEMP, 0.002),
> which will at the end
> occupy all degenerate states partially.
> 
> In addition: N should be done spin polarized!! This
> will occupy the 3
> spin-up p orbitals fully, the spin-dn states are
> empty and I would not
> expect any convergence problems.
> 
>                                       P.Blaha
>
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> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna,
> A-1060 Vienna
> Phone: +43-1-58801-15671             FAX:
> +43-1-58801-15698
> Email: blaha at theochem.tuwien.ac.at    WWW:
> http://info.tuwien.ac.at/theochem/
>
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