[Wannier] anything wrong with my wannier calculation?

[Jonathan Yates]

Mithra,

 Quoting your post on the pw forum

"However, the final result of $NAME_hr.dat shows that the wannier orbitals are nonorthogonal on the same site because the overlap matrix has non-zero elements among wannier orbitals either on the Ga or on the As."

The <seedname>_hr.dat file contains the matrix elements of the Hamiltonian between Wannier orbitals. It is not the overlap matrix. The MLWF are constructed to be orthogonal. We don't explicitly construct the overlap matrix - but I guess you could if you really wanted to check.. (bit expensive - and a few things to watch with usp's/paw)

 Jonathan



On 27 Oct 2010, at 12:35, Mithra Chan wrote:

> Dear Nicola,
> 
> Thanks for your reply. Now I move to wannier at quantum-espresso.org to continue the discussion on my problem which was posted in pw_forum. I am sorry I missed a lot of details of my calculations.
> Concerning the points you mentioned in the previous post,
> (1) I have plotted all the wannier orbitals, 4 on Ga and another 4 on As, all is sp3 type. 
> 
> (2) I did a disentanglement with 300 iterations. 
> 
> (3) The interpolated bands are in good agreement for the lowest four bands but for others there are some discrepancies, not too many. Roughly can be accepted.
> 
> The overlap matrix contains elements like:
> 
>    ....  
>     0    0    0    1    1    6.345104    0.000000
>     0    0    0    2    1   -1.821392    0.000760
>     0    0    0    3    1   -1.805869   -0.005628
>     0    0    0    4    1    1.802236    0.009446
>     0    0    0    5    1    0.704917    0.000565
>     0    0    0    6    1    0.683556    0.001387
>     0    0    0    7    1    0.686007    0.003743
>     0    0    0    8    1    0.682286    0.002777
>    ...
> 
> My input parameters are:
>   ********************** $NAME.win ****************
> 
> ! Gallium Arsenide: Tutorial Example 1
> 
>  num_wann    =  8
>  num_iter    =  300
>  num_bands   =  12
> 
>  dis_win_min  = -8
>  dis_win_max  =  18
>  dis_num_iter =  300
> 
> wannier_plot = true
>  hr_plot     = true
> bands_plot   = true
> 
> begin unit_cell_cart
> bohr
> -5.341313   0.000000   5.341313
>  0.000000   5.341313   5.341313
> -5.341313   5.341313   0.000000
> end unit_cell_cart
> 
> begin atoms_frac
> Ga 0.00   0.00   0.00
> As 0.25   0.25   0.25
> end atoms_frac
> 
> begin projections
> Ga:l=0;l=1
> As:l=0;l=1
> end projections
> 
> begin kpoint_path
> L   0.00   0.00   -0.50        G   0.00   0.00    0.00
> G   0.00   0.00    0.00        X  -0.50   0.00   -0.50
> X  -0.50   0.00   -0.50        K  -0.375 -0.375  -0.75
> K  -0.375 -0.375  -0.75      G   0.00   0.00    0.00
> end kpoint_path
> 
> mp_grid : 3 3 3
> 
> begin kpoints
>    0.0000000    0.0000000    0.0000000
>   -0.3333333   -0.3333333    0.3333333
>   -0.6666667   -0.6666667    0.6666667
>    0.3333333    0.3333333    0.3333333
>    0.0000000    0.0000000    0.6666667
>   -0.3333333   -0.3333333    1.0000000
>    0.6666667    0.6666667    0.6666667
>    0.3333333    0.3333333    1.0000000
>    0.0000000    0.0000000    1.3333333
>   -0.3333333    0.3333333   -0.3333333
>   -0.6666667    0.0000000    0.0000000
>   -1.0000000   -0.3333333    0.3333333
>    0.0000000    0.6666667    0.0000000
>   -0.3333333    0.3333333    0.3333333
>   -0.6666667    0.0000000    0.6666667
>    0.3333333    1.0000000    0.3333333
>    0.0000000    0.6666667    0.6666667
>   -0.3333333    0.3333333    1.0000000
>   -0.6666667    0.6666667   -0.6666667
>   -1.0000000    0.3333333   -0.3333333
>   -1.3333333    0.0000000    0.0000000
>   -0.3333333    1.0000000   -0.3333333
>   -0.6666667    0.6666667    0.0000000
>   -1.0000000    0.3333333    0.3333333
>    0.0000000    1.3333333    0.0000000
>   -0.3333333    1.0000000    0.3333333
>   -0.6666667    0.6666667    0.6666667
> end kpoints
> 
>    ********************
> 
> Any suggestion? Thanks a lot.
> 
> Best regards,
> 
> Mithra 
> 
> 
> -- 
> Dr. Mithra Chan,
> Department of Physics, National University of Singapore, Singapore
> chan.mithra at gmail.com
> 
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