[Wien] lapwdm (bis)

[Pavel Novak]

Dear Stefaan,

using bcc Fe I checked that indeed there is a bug when calculating <X> in
lapwdm. My preliminary conclusion are:
1/ if the spin co-ordinate system is the same as crystal system everything
is OK and both methods of calculating Lz lead to the same result.
2/ for rotated co-ordinate system there is a bug when <X> is calculated
(e.g. .indmc ends with 1 3 .. Lz). Lz is still correct if calculated by
the 1st method - directly from the density matrix. Note that it must be
called as
x lapwdm -c -so -up
if instead it is called with
x lapwdm -c -so -dn
Lz would have an opposite sign.

Unfortunatelly I'll  be out of the Institute for the rest of the
week, but next week I'll put the bug on my priority list.

Pavel

On Wed, 17 Sep 2003, Stefaan Cottenier wrote:

> Dear Wien-users,
>
> I did some more tests on the lapwdm 'problem' (?) I posted a few days ago
> (see copy below). I could reproduce the problem in bulk bcc Fe, which makes
> testing much easier. First I converge the case with spin-orbit and with the
> moment in case.inso either along 001 or 100 (010 doesn't seem to work, but
> all these 3 cases should be equivalent anyway). Then I run 'x
> lapwdm -c -so -up' twice: once with '0 0' in case.indmc, once with '1 3'. In
> both cases I see the following output in case.scfdmup:
>
> For '0 0':
> :ORB001:  ORBITAL MOMENT:  0.04682  0.00000  0.00000 PROJECTION ON M
> 0.04682
>
> For '1 3':
> :XOP001  2    -0.02690     0.00000     0.07372     0.04682
>
> This is entirely as I expect: both procedures yield the same orbital moment.
>
> But then, instead of 001 or 100, I specify 110 in case.inso (which gives 8
> instead of 16 symmetry operations). Now both procedures yield *different*
> orbital moments, just as I reported a few days ago for a more complicated
> cell:
>
> For '0 0':
> :ORB001:  ORBITAL MOMENT:  0.03325  0.03325  0.00000 PROJECTION ON M
> 0.04702
>
> For '1 3':
> :XOP001  2     0.00000     0.00000     0.00000     0.00000
>
> I can now repeat my original question on firmer grounds: "Should both
> procedures (00 and 13) be equivalent as I assumed up to now, or do they
> calculate different quantities ?"
>
> Stefaan
>
>
>
> ----- Original Message -----
> From: "Stefaan Cottenier" <Stefaan.Cottenier at fys.kuleuven.ac.be>
> To: <wien at zeus.theochem.tuwien.ac.at>
> Sent: Monday, September 15, 2003 12:33 PM
> Subject: [Wien] lapwdm
>
>
> > Dear Wien-users,
> >
> > I have a problem interpreting the output of lapwdm. After a k-point
> parallel
> > calculation with spin-orbit coupling included, I run 'x
> > lapwdm -c -so -up -p' with '0 0' in the last line of case.indmc. In
> > case.scfdmup, I see -- among much other information -- the orbital moment
> of
> > the first atom in my case.struct:
> >
> > :ORB001:  ORBITAL MOMENT:  0.03087  0.02869  0.00000 PROJECTION ON M
> > 0.04210
> >
> > Now I change the last line of case.indmc to '1 3', in order to get only
> the
> > orbital moment written to case.scfdmup, and run lapwdm again.
> Surprisingly,
> > now it reads
> >
> > :XOP001  2     0.00047     0.00000     0.00105     0.00152
> >
> > In my understanding, these are two equivalent ways to obtain the orbital
> > moment in wien2k, so I didn't expect numbers that are so different as
> 0.0421
> > and 0.0015. Also, in all other cases I saw before, these two procedures do
> > yield identical numbers. Is this a bug, or do these two numbers maybe
> refer
> > to 2 different quantities, and not both to 'the' orbital moment ? Can
> > somebody comment?
> >
> > While trying to find an answer, I found the following information that
> maybe
> > can be helpful. In case.outputdm_1up, I read for the first set of k-points
> > and for the first atom this sentence for '1 3' :
> >
> > DENSITY MATRIX IN LOCAL COORD. SYSTEM of repre. atom
> >  spin coordinate system according to case.inso
> >
> > Apparantly, with '1 3' lapwdm takes into account information from
> case.inso,
> > while with '0 0' it maybe does not? This is my case.inso:
> >
> > WFFIL
> >  4  1  0                      llmax,ipr,kpot
> >  -10.0000   1.50000           emin,emax (output energy window)
> >    1.  1.  0.                 direction of magnetization (lattice vectors)
> >  0                            number of atoms for which RLO is added
> >  0 0 0 0 0                    number of atoms for which SO is switch off;
> > atoms
> >
> > All other cases that worked well, had two zero's in the direction of
> > magnetization, this case is the first I try with the moment not along one
> of
> > the main axes of case.struct. Maybe that is related to my problem?
> >
> > Thanks,
> > Stefaan
>
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