<div dir="ltr">Dear Aron,<div><br></div><div>Thank you for your detailed explanations and suggestions. I will tried it out.</div><div><br></div><div>I have no idea of why your wannier functions are more compact for super cell. I usually use primitive cell instead of supercell. Does anyone have clue on Aron's issue?</div><div><br></div><div>Best</div><div><br></div><div>Yu<br><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Feb 12, 2015 at 7:30 AM, Aron Szabo <span dir="ltr"><<a href="mailto:szaboa@iis.ee.ethz.ch" target="_blank">szaboa@iis.ee.ethz.ch</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Dear Yu,<br>
<br>
I was also working on gold recently. As Nicola said, you should
include the lowest two bands too. The other thing is that you
should use the disentanglement method instead of just excluding
the topmost bands, because they are entangled. When you exclude
the n-th band it means that at every k-point the state with the
n-th energy is excluded. It is not what you want when bands are
crossing each other, because e.g. at the W point in your band
structure you should keep the topmost blue line because that is
the one "smoothly connected" to the lower energy states, although
it has a higher energy at W than the other below it that you
should exclude. The disentanglement method finds these optimally
connected bands. The third thing is that you should try to set an
sp3 hybrid as an initial projection instead of the s orbital. I
found that it converges better. The center of this Wannier
function should move away from the gold atom, but if you choose an
s orbital centered on the atom, it will stay in a local minimum
due to it's symmetry. So I would recommend these settings:<br>
<br>
<div>num_wann = 12<br>
</div>
<div>num_bands = 16<br>
<br>
dis_froz_max = 2<br>
#dis_froz_min = -2<br>
dis_win_max = 7<br>
<br>
spinors = .true.</div>
<div>Begin Projections</div>
<div>Au: sp3-1;l=2 </div>
<div>End Projections</div>
<br>
<br>
You can also set a value for dis_froz_min, though it's not
absolutely necessary. The default is just the lowest energy.
States between dis_froz_min and dis_froz_max will be reproduced
exactly by the Wannierization, but usually the larger interval you
set, the larger the spread of the Wannier functions will be, due
to the more constraint. Therefore you should set it only around
those energies that you need to reproduce exactly, e.g: close to
the Fermi energy if you want to calculate transport later.<br>
<br>
There is just one strange thing I've found and don't know why it
happens: if I create a 4-atomic cubic cell instead of the
primitive 1-atomic FCC cell, I get somewhat more compact Wannier
functions with the exact same settings. Does anyone have a clue
why is that? I've observed it in many cases that if I create a
supercell with a different space group than the primitive cell
(e.g. a rectangular cell made of two hexagonal unit cells of MoS2)
the Wannierization might fail. And now it's the opposite, I get
better results with a supercell.<br>
<br>
Best,<br>
Aron Szabo<div><div class="h5"><br>
<br>
On 02/12/2015 05:16 AM, Yu Zhang wrote:<br>
</div></div></div>
<blockquote type="cite"><div><div class="h5">
<div dir="ltr"><span style="font-size:12.8000001907349px">Dear
wannier90 users and developers, </span>
<div style="font-size:12.8000001907349px"><br>
</div>
<div style="font-size:12.8000001907349px">I am using
wannier90-1.2 and vasp5.3 to obtain the wannier wave function
of gold with spin-orbital coupling. I used d5s orbital as
target. However, it ends up with some wiggly bands as shown by
the attached figure. I have tried different projection (d5),
and k-mesh, but I still failed to get the smooth bands. Does
anyone know what causes the wiggly bands and how to get rid of
them?</div>
<div style="font-size:12.8000001907349px"><br>
</div>
<div style="font-size:12.8000001907349px"><br>
</div>
<div style="font-size:12.8000001907349px">My wannier90 input
file is:</div>
<div style="font-size:12.8000001907349px">===========================================</div>
<div style="font-size:12.8000001907349px">
<div>num_wann = 12 ! set to NBANDS by VASP</div>
<div>num_bands = 12</div>
<div><br>
</div>
<div>exclude_bands : 1-2, 15-16</div>
<div><br>
</div>
<div>spinors = .true.</div>
<div>Begin Projections</div>
<div>Au: l=0;l=2 </div>
<div>End Projections</div>
<div><br>
</div>
<div>begin unit_cell_cart</div>
<div> 0.0000000 2.0340000 2.0340000</div>
<div> 2.0340000 0.0000000 2.0340000</div>
<div> 2.0340000 2.0340000 0.0000000</div>
<div>end unit_cell_cart</div>
<div><br>
</div>
<div>begin atoms_cart</div>
<div>Au 0.0000000 0.0000000 0.0000000</div>
<div>end atoms_cart</div>
<div><br>
</div>
<div>mp_grid = 21 21 21</div>
</div>
<div style="font-size:12.8000001907349px"><br clear="all">
<div>
<div>begin kpoints</div>
<div> 0.000000000000 0.000000000000
0.000000000000</div>
<div> 0.047619047619 0.000000000000
0.000000000000</div>
<div> 0.095238095238 0.000000000000
0.000000000000</div>
<div> 0.142857142857 0.000000000000
0.000000000000</div>
<div> 0.190476190476 0.000000000000
0.000000000000</div>
<div>.......</div>
</div>
<div>==================================================</div>
<div><br>
</div>
<div>Thank you very much in advance!</div>
<div><br>
</div>
<div>Best regards,</div>
<div><br>
</div>
<div>Yu Zhang</div>
</div>
</div>
<br>
<fieldset></fieldset>
<br>
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</span></blockquote>
<br>
</div>
</blockquote></div><br></div></div></div>