[Wannier] bto wannier functions

[Nicola Marzari]

Hi Vivek,

I did study different group of bands separately - e.g.
the O 2s bands, with three spherically symmetric gaussians,
or the O 2p bands, with p_x, p_y, p_z orbitals on each
oxygen. I had 20 bands in total (18 electrons from the oxygens,
10 from the Ba, 12 from the Ti) and these were all the combinations
I used, depending on the different groups of bands I was looking at
(sometimes I would look at Ba 3p and O 2s together, or separately).

In the fourth column, 0 means s, 1 means p, and in the fifth columun
-1 0 and 1 mean px py and pz. note that that this is an old notation,
superseded in the current wannier.

				nicola


1band/wannier.centers
::::::::::::::
    0.500000   0.500000   0.500000  0  0
::::::::::::::
3bands_Ba/wannier.centers
::::::::::::::
    0.000000   0.000000   0.000000  1 -1
    0.000000   0.000000   0.000000  1  0
    0.000000   0.000000   0.000000  1  1
::::::::::::::
3bands_O/wannier.centers
::::::::::::::
    0.000000   0.500000   0.500000  0  0
    0.500000   0.000000   0.500000  0  0
    0.500000   0.500000   0.000000  0  0
::::::::::::::
4bands/wannier.centers
::::::::::::::
    0.000000   0.000000   0.000000  0  0
    0.500000   0.500000   0.500000  1 -1
    0.500000   0.500000   0.500000  1  0
    0.500000   0.500000   0.500000  1  1
::::::::::::::
6bands/wannier.centers
::::::::::::::
    0.000000   0.000000   0.000000  1 -1
    0.000000   0.000000   0.000000  1  0
    0.000000   0.000000   0.000000  1  1
    0.000000   0.500000   0.500000  0  0
    0.500000   0.000000   0.500000  0  0
    0.500000   0.500000   0.000000  0  0
::::::::::::::
9bands/wannier.centers
::::::::::::::
    0.000000   0.500000   0.500000  1 -1
    0.000000   0.500000   0.500000  1  0
    0.000000   0.500000   0.500000  1  1
    0.500000   0.000000   0.500000  1 -1
    0.500000   0.000000   0.500000  1  0
    0.500000   0.000000   0.500000  1  1
    0.500000   0.500000   0.000000  1 -1
    0.500000   0.500000   0.000000  1  0
    0.500000   0.500000   0.000000  1  1



Vivek Ranjan wrote:
> Hi !
> 
> I want to know how the intial guess wannier functions of BaTiO_3 was
> chosen for producing fig.2, pg 133, of An Introduction to the
> Maximally-Localized Wannier Functions by Nicola Marzari, Ivo Souza, and
> David Vanderbilt, Scienticfic Highlight of the Month, Psi-K Newsletter 57,
> 129 (2003).
> 
> I am using a single gaussian functions with five centers (Ba, Ti, and
> three O)  : s and d type centered on Ba, s and p type centered on Ti, and
> three oxygens. Is this OK ? I want to calculate polarization within the
> unit cell of BaTiO_3 as well as make some nice figures.
> 
> 
> 
> Thank you,
> Vivek
> 
> 
> __________________________________________________________________________
> web : http://www.geocities.com/vivekranjanweb
> __________________________________________________________________________
> Vivek Ranjan                             Email : vranjan at chips.ncsu.edu
> Center for High Performance Simulation         : vranjan at ncsu.edu
> Department of Physics
> NC State University                      Phone : +1-919-513-0613 (Office)
> Campus Box 7518                          Fax   : +1-919-513-4804
> Raleigh, NC 27695
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Prof Nicola Marzari   Department of Materials Science and Engineering
13-5066   MIT   77 Massachusetts Avenue   Cambridge MA 02139-4307 USA
tel 617.4522758 fax 2586534 marzari at mit.edu http://quasiamore.mit.edu