[Wannier] large spreeds for some WFs

[lan haiping]

Dear All,

  I am trying to  study  disentanglement of wannier with nanotube (10 0) by
including several conduction bands.
There are some problems  that i didnot come to for the cases of only valence
bands included.
First , it takes me long time to reach the convergence thread for
disentangle process. I just tried to tune dis_mix_ratio , but there is no
much effect.  In my calculation, I had included 130 bands for disentangling
100 WFs, it would take about 4000 iterations to reach convergence no matter
what dis_mix_ratio i set to.  This value is of course seriouly larger than
the default value (200).
Though there are a few parameters for disentanglement, i donot have much
idea about
energy window settings for disentanglement and frozen energy window. Could
we just set dis_win_min to conduction bands' bottom in my semiconducting cnt
case  ?  I also tried to set frozen energy window , but there was no much
effect for improving convergence. Could  the proper frozen energy window
improve convergence ?  and would you please tell how to set up frozen energy
window properly ?

Another question is about large spreads for some WFs after
wannierise.Afterwannierise process, there are mainly 3 groups of
spreads of WFs. Spreads of
first group are around 0.6- 0.7,  while 1.6-2.4 are for second group. There
are 2 WFs for third group, of  spreads around 7.0 ,which are great larger
than  that of other two group. Does such result have proper physical meaning
?
Any comments will be appreciated.     As far as i know, large spreads of WFs
may not be suitable for tight binding calculation . Are there any methods or
settings to obtain smaller spreads of  WFs ?

Best Wishes,

 hai-ping
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