[Wannier] ERROR: unitarity of initial U

[Arash Mostofi]

Dear Gianluca,

There was a related post on this mailing list last year:

http://www.democritos.it/pipermail/wannier/2011-October/000461.html

Please could you check whether the error is reproducible with different 
libraries/compilers, and report back?

Best wishes,

Arash

--
Dr Arash A Mostofi
Departments of Materials and Physics
Deputy Director, CDT on Theory and Simulation of Materials
Imperial College London, London SW7 2AZ, UK
+44 (0)207 594 8154 | www.cmth.ph.ic.ac.uk/people/a.mostofi

On 02/11/2012 14:32, Gianluca Giovannetti wrote:
> Dear All,
>
> i`m working on extracting the Wannier functions of LiV2O4.
> The trigonal symmetry splits the low-lying t_{2g} levels into one a_{1g}
> and two degenerate e_{g}^pi levels, with the former slightly lower in
> energy and narrower in bandwidth. The density of states looks very simple.
> At Fermi level there are Vanadium d bands having a bandwidth of ~ 2eV.
> Below in energy separated from the Vanadium d bands there are bands with
> predominant Oxygen p bands.
> I can extract with no problem the Vanadium d bands using an energy
> window sitting at the Vanadium d bands.
> Wannier90 bands are on top of DFT bands (i also compared mine with some
> known in literature).
> As a starting point for the projection i used:
>
> begin projections
> V:dxz;dyz;dxy
> end projections
> Once i try to calculate Wannierfunctions for "d" and "p" orbitals i get
> the following error:
>
>     A_mn = <psi_m|g_n> --> S = A.A^+ --> U = S^-1/2.A
>     In dis_project...  ERROR: unitarity of initial U
>   nkp=  1
>   i=  2  j=  4
>   [u_matrix_opt.transpose(u_matrix_opt)]_ij=     0.114936    -0.050292
>   Exiting.......
>   dis_project: Error in unitarity of initial U in dis_project
>
> Do you have any idea for solving it?
> Below it is my input file.
>
> thank you in advance.
>
> Gianluca Giovannetti
>
> =========================
>
> iprint = 3
> num_bands       = 70
> num_wann        = 36
>
> num_iter        =  2000
> num_print_cycles = 100
>
> dis_win_max     = 9.1
> dis_win_min     = -0.5
>
> dis_num_iter    = 200
> dis_mix_ratio   = 0.75
>
> write_r2mn=.true.
> hr_plot=.true.
>
> kmesh_tol=0.00001
>
> ! SYSTEM
>
> begin unit_cell_cart
> bohr
> 7.789167066 0.0000 7.789167066
> 0.0000 7.789167066 7.789167066
> 7.789167066 7.789167066 0.0000
> end unit_cell_cart
>
> begin atoms_cart
> Ang
> V    0.000000    0.000000    0.000000
> V    2.060925    2.060925    0.000000
> V    2.060925    0.000000    2.060925
> V    0.000000    2.060925    2.060925
> O     0.094555000   0.094555000  1.966370000
> O     1.966370000   1.966370000  1.966370000
> O     0.094555000   1.966370000  0.094555000
> O     1.966370000   0.094555000  0.094555000
> O    -0.094556000   4.027295000  2.155480000
> O     2.155480000  -1.966370000  2.155480000
> O    -0.094556000  -1.966370000 -0.094556000
> O     2.155480000   4.027295000 -0.094556000
> Li     1.030463000   5.152312000  1.030463000
> Li     3.091388000   3.091388000  3.091388000
> end atoms_cart
>
> begin projections
> V:dxz;dyz;dxy
> O:px;py;pz
> end projections
>
> begin kpoint_path
> G 0.00  0.00  0.00    X 0.00  0.50  0.50
> X 0.00  0.50  0.50    W 0.25  0.75  0.50
> W 0.25  0.75  0.50    L 0.00  0.50  0.00
> L 0.00  0.50  0.00    G 0.00  0.00  0.00
> end kpoint_path
> bands_plot = .true.
>
> !To plot the WF
> !wannier_plot = T
> !wannier_plot_supercell = 2
> !wannier_plot_list = 1-12
> !restart = plot
>
> ! KPOINTS
>
> mp_grid : 8 8 8
>
> begin kpoints
> .............
>
>
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