[Wien] nonzero energy for zero-electron system

[Robert Laskowski]

Hi,
did you add background charge in mixer, if not this is maybe related to the difference in 
nuclear and electronic charges, I think mixer tries to keep the cell neutral.

regards 

On Tuesday 09 February 2010 16:12:18 Yurko Natanzon wrote:
> Dear prof. Blaha,
> That you for your reply. Yes, the problem lies in the density
> integrals (:DEN), all the other terms are zero. I've looked at the
> clm* files and found out that the valence and core charge density are
> zero, but the total density in clmsum is not zero inside the MT sphere
> (and is zero in the interstitial). However, it is quite small, the
> C_lm coefficients are about 10^-25, and it is quite a surprize that
> the total energy is so high.
> 
> I've played with changing the number of k points, RKmax, changed basis
> from LAPW to APW. Also, I've tried LDA and GGA functionals, but the
> result is the same: :DEN = -0.21117633
> 
> The only non-zero potential in Kohn-Sham equations will be the
> external potential -1/R, but still this doesn;t explain why the
> density ingerals are non-zero. Could you explain in more detail, how
> these density integrals are calculated and why they are non-zero while
> the density is near zero?
> 
> with kind regards,
> Yurko
> 
> On 8 February 2010 20:10, Peter Blaha <pblaha at theochem.tuwien.ac.at> wrote:
> > Please check your scf-file.
> > E-tot comes from 3 contributions:
> >
> > :DEN    the density-potential-Exc integrals. When rho=0, this should be
> > zero.
> > :SUM    the sum of occupied eigenvalues (should be zero in your case)
> > :1s     the core eigenvalues, which again should be zero.
> >
> > I'd expect problems in :DEN, maybe because the density is not yet zero, but
> > the scf cycle stopped
> >
> > Yurko Natanzon schrieb:
> >>
> >> Dear Wien2k users and developers,I'm trying to calculate the total energy
> >> of the hydrogen atom with anelectron removed (actually, a proton). the atom
> >> is located in thecentre of 13*13*13 Bohr cubic cell, the number of electrons
> >> incase.in2 as well as the occupation numbers in case.inst was set tozero.
> >> As it was expected, the calculated electron density is zero, but thetotal
> >> energy is not and equals to -0.2111 Ry. So the question is, whyit does not
> >> equal to zero and what is the meaning of this number?
> >> with kind regards,Yurko
> >>
> >> -- Yurko (aka Yuriy, Iurii, Jurij etc) NatanzonPhD studentDepartment for
> >> Structural Research (NZ31)Henryk Niewodniczański Institute of Nuclear
> >> PhysicsPolish Academy of Sciencesul. Radzikowskiego 152,31-342 Krakow,
> >> PolandE-mail: Yurii.Natanzon at ifj.edu.pl,
> >> yurko.natanzon at gmail.com_______________________________________________Wien
> >> mailing
> >> listWien at zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> >
> > --
> > -----------------------------------------
> > Peter Blaha
> > Inst. Materials Chemistry, TU Vienna
> > Getreidemarkt 9, A-1060 Vienna, Austria
> > Tel: +43-1-5880115671
> > Fax: +43-1-5880115698
> > email: pblaha at theochem.tuwien.ac.at
> > -----------------------------------------
> > _______________________________________________
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> > Wien at zeus.theochem.tuwien.ac.at
> > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> >
> 
> 
> 



-- 
Dr Robert Laskowski

Vienna University of Technology, 
Institute of Materials Chemistry, 
Getreidemarkt 9/165-TC, A-1060 Vienna

tel. +43 1 58801 15675
Fax  +43 1 58801 15698