[Wien] density matrix normalization - expectation spin value

[Martin Gmitra]

Hi Robert,

Actually we are interested in SOC case. Could you please provide some
further hints how to get the off-diagonal part for spin density matrix?

Martin



On Fri, Feb 5, 2010 at 9:47 AM, Robert Laskowski <
rolask at theochem.tuwien.ac.at> wrote:

> Yes, lapw2 calculates also interstitial charge density (fourir.F). You can
> try to hack this, and add a routine that integrates
> the charge density in interstitia, there should be one in mixer source.
> Then interface it with your modified version of lapwdm.
>
> lapw2 does not calculate the off diagonal part of the spin density matrix,
> which is non zero if SOC is present.
> If you are not interested  in SOC, then easiest would be to use filtvec
> program that filters vectors, strip it from  all
> states except the one you are interested in and run lapw2 and mixer to get
> the charge in interstitial.
>
>
> regards
>
> On Thursday 04 February 2010 20:16:29 Martin Gmitra wrote:
> > Hi Robert,
> > Is there a way to include this somehow?
> > Thanks,
> > Martin
> >
> >
> > On Thu, Feb 4, 2010 at 9:44 AM, Robert Laskowski <
> > rolask at theochem.tuwien.ac.at> wrote:
> >
> > > Hi,
> > > you are missing interstitial contribution.
> > >
> > > regards
> > >
> > > On Thursday 04 February 2010 09:36:53 Martin Gmitra wrote:
> > > > Dear Wien2k users,
> > > >
> > > > We are interested in calculation of expectation value of spin for a
> state
> > > |n,k>,
> > > > where n is the band index and k is the wave vector. For this purpose
> we
> > > have
> > > > slightly modified lapwdm program. The problem we are encountering is
> that
> > > the
> > > > expectation value of z-component of Pauli matrix (sigma_z) is not
> equal
> > > one.
> > > > Let us assume for simplicity spin-up state |n,k> and no spin-orbit
> > > coupling.
> > > > The expectation value for sigma_z we calculate as
> > > >
> > > > sum_a ( rho_{n,k,a} sigma_z ) not= 1  (it is smaller then 1, typical
> > > > range 0.6-0.9)
> > > >
> > > > where sum_a is the summation over atoms in unit cell.
> > > >
> > > > 1. Why we do not obtain for the state |n,k> expectation value equal
> one?
> > > > It is rather obvious that in this example <n,k| sigma_z |n,k> =1.
> > > >
> > > > 2. What is the density matrix normalization in this case?
> > > >
> > > > rho_{n,k,a} is in this simple example 2x2 matrix having only up-up
> > > component,
> > > > which is given as Trace in orbital subspaces (sum for L=0,1,2,3) of
> given
> > > state
> > > > |n,k>.
> > > >
> > > > Many thanks in advance,
> > > > Martin
> > > >
> > > > [We are running Wien2k v9.1]
> > > > _______________________________________________
> > > > Wien mailing list
> > > > 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
> > > _______________________________________________
> > > Wien mailing list
> > > 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
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>
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