[Wien] Band character plotting and Linearization energy

[Peter Blaha]

> (1) Is it true that band character plotting is still not possible for
> spin-polarized with SOC?
> 
> I succeeded for the one without SOC, but not with
> SOC. Note the band structure plotting is fine for either case, just the
> characterer plotting is not working.
> 
>  In my case.insp file,  I have
> 1.1   0    4                      # line width, line switch, color switch

A line-switch of 0 will NEVER do "character plotting". You need 2 or 3
   2...lines and open circle
   3...lines and filled circles

And yes, I think character plotting works also for spinpolarized + SO cases.

> (2) Linearization energy selection, and a failure  similar to
> Stefaan's
> 
> I followed Stefaan's excellent notes closely and tested it with C60 solid.
> 
> -------------------First question--------------------
> 
>  The default global linearization energy parameter in case.in1 is
> very different from the real DOS, but the job runs fine and converges as
> well.
> 
> This is the default case.in1
> 
> WFFIL        (WFPRI, SUPWF)
>   7.00       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>   0.30    3  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
>  0  -0.77605   0.01000CONT 1
>  0   0.30000   0.00000CONT 1
>  1   0.30000   0.00000CONT 1
> ...
> K-VECTORS FROM UNIT:4   -9.0       3.0   140   red   emin/emax/nband
> 
> When I checked the DOS, I found the main DOS before the Fermi level is
> around -0.3, but the default global energy is 0.30 (see above).
> 
> Is this normal?

It is not "normal", but it can happen for open structures, surfaces,...

> I understand the sp states spread quite a big region. (-in1new was also
> tested, but no too difference). I then changed
> select.f's upper bound (in Lapw1) from 0.5 to 4.5 to cover those highly energy
> states to get a  better linearization energy. This does not change the
> default case.in1

Why should select.f in lapw1 change the input file of lapw1 ???
It may have an effect on the actual energies used (see the scf1 file!!!)

If you use -in1new, this should give a very different case.in1 file!

For sp states, often the energy parameters are quire insensitive, so you may not
see any difference in the DOS.


> After a first run, I plot total and partial dos and create a new case.in1
> WFFIL        (WFPRI, SUPWF)
>   7.00       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>  -0.31    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
>  0  -0.36000   0.00500CONT 1 <----- 2 S state's center below Ef
>  0   1.40000   0.00000CONT 1 <----- center of 2S* states I need
>  1  -0.32000   0.00500CONT 1 <----- 2 P state's center below Ef
>  1   1.50000   0.00000CONT 1 <----- center of empty 2P* states I need
> ....
> K-VECTORS FROM UNIT:4   -9.0       3.0   140   red   emin/emax/nband
> 
> When I run my job with this input file, I found WIEN2K_06 version crashed
> at lapw1 (due to Seclr4.F), and then I dumped overlap matrix. I found that
> clearly some of basis functions appear to be linearly dependent. On a
> different cluster (larger memory and disk, the matrix can be very large),
> I ran WIEK2k_08 and found it is working fine but there are some states
> below -9 for quite a few k points. These states must be wrong since free
> carbon atom's 1s energy is around -9, but this error is very similar to
> Stefaan's finding.

First of all again: check the actual energies used in lapw1, which are printed
in case.scf1. As soon as you "search" (the 0.005 just before the CONT) you may
actually use quite different energies.

Second: for small spheres (you said C60, and this must have very small spheres)
the radial wavefunctions (inside the sphere) at expansion energies of -0.3 and 1.3
might still be very similar leading to linear dependency. Whether the LAPACK detects
linear dependencies and stops or it continues depends probably a lot on the BLAS/lapack
software and small numerical details. But "eigenvalues below ..." always hints to
linear dependency problems.

Are you sure the center of 2s and 2p energies are that close together? (-0.36/-0.32)
What does the scf2 file or case.in1 after in1new say ?

-- 

                                       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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