[Wannier] about the wannier90_hr.dat file

[Gianluca Giovannetti]

Dear All,

i have performed calculations on a organic molecular crystal using PW code.
doing this i reproduce correctly the band structure i found in the
literature.

i have then used WANNIER90 code to get the Hamiltonian matrix elements
(written in wannier90_hr.dat file) as i want to know the hopping parameters
between different molecular sites.

Once i plot the file wannier90_band.dat produced by WANNIER90 these bands
correctly reproduce the PW bands.
Moreover the file wannier90_hr.dat file seems to contain reasonable
informations.

However in the wannier90.wout the spread of one of the Wannier functions is
very large (----> 152.37216676):

 Cycle:   1000
  LINE --> Iteration                     :        1000
  LINE --> Spread at initial point       :   181.645172268384
  LINE --> Spread at trial step          :   181.645172268384
  LINE --> Slope along search direction  : -2.431285074681767E-017
  LINE --> ||SD gradient||^2             :  2.434718719629064E-015
  LINE --> Trial step length             :   2.00000000000000
  LINE --> Optimal parabolic step length :  3.420559126041558E-004
  LINE --> Spread at predicted minimum   :   181.645172268384
  LINE --> CG coefficient                :  0.999997853070419
  WF centre and spread    1  (  6.466896,  3.625330,  2.430574 )
152.37216676
  WF centre and spread    2  (  5.485734,  9.409137,  8.702740 )
9.81928932
  WF centre and spread    3  (  7.666070,  4.358506,  8.556600 )
9.83226929
  WF centre and spread    4  (  3.155228,  4.303197,  8.509269 )
9.62144690
  Sum of centres and spreads ( 22.773929, 21.696169, 28.199184 )
181.64517227

   1000     0.000E+00     0.0000000493      181.6451722684      36.56  <--
CONV
        O_D=    142.5795768 O_OD=      0.0828030 O_TOT=    181.6451723 <--
SPRD
 Delta: O_D=  0.0000000E+00 O_OD=  0.2692291E-14 O_TOT=  0.0000000E+00 <--
DLTA
 ------------------------------------------------------------------------------

The 4 WFs should have more or less the same spread.

Attached the input file for WANNIER90 i used.

I have two questions:

1) Can i trust the output file wannier90_hr.dat in this case?

2) How can i get a small SPREAD?

i thank you in advance.

cheers,

Gianluca Giovannetti

http://www.sissa.it/main/?p=PHONEBOOK&surname=Giovannetti&name=Gianluca
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