DearĀ Erica, dear Lorenzo,
just to add to what Lorenzo said:
* as far as I know mostly the PAW coded write the pseudo-wavefunction
into the UNK files, therefore the number of nodes cannot be
reproduced in Wannier functions. At least it is true forĀ VASP and
QuantumEspresso. The reasons are twofold: (i) noone bothered to code
plotting all-electron wavefunction, (ii) the all-electron
wavefunction strongly oscillates near the core, therefore a very
dense real-space grid is needed to represent it.
* The Wannier function may have additional nodes far from the the
center (usually near the neighboring atoms, or even further) but
those are not related to the nodes of atomic wavefunctions.
* According to the page http://www.wannier.org/features/ , Wannier90
is interfaced with Fleur and Wien2k, but I am not familiar with
those, I do not know if/how they write the UNK files.
* I fully agree with Lorenzo's conclusion:
Finally, if all you need is a pretty picture, I don't think it is
worth it. If you need the correct all-electron wavefunction close
to the core, I'm not sure wannierization is the best method.
Regards,
Stepan
On 03.11.20 10:41, Lorenzo Paulatto wrote:
On 11/3/20 7:55 AM, Erica Kotta wrote:
The plots in xcrysden I've come across only show the lowest-level
orbitals for each l-value (for example only 2p orbital character,
even when you know that the bands of interest are 3p or 4p). I
thought that by getting the underlying xsf numerical data or
recreating the plots from the Umn/UNK files, I would be able to
resolve the "missing" nodes.
Hello Erica,
this is not a limitation of the wannierization method, but of the
pseudo-potential approximation. The Wannier90 only works with what it
gets from the total energy code.
I don't know if Wannier90 can interface with any all-electron code
In principle if you use PAW pseudopotential, or with a GIPAW-like
method, it is possible to reconstructs the all-electron wavefunctions
from a pseudopotential calculation, but I do not think it has ever
been done in conjunction with wannierization.
Finally, if all you need is a pretty picture, I don't think it is
worth it. If you need the correct all-electron wavefunction close to
the core, I'm not sure wannierization is the best method.
cheers
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