[Wannier] several questions about wannier calculation and settings

[lan haiping]

Hi.
 I tried to calculation anatase tio2 wannier center with wannier, but  came
to several failures with different error complains.

one question is about kmesh setting:
   when i use 3x3x3 (or 4x4x2) mp grids , wannier could generate data
tio2.nnkp without complain. But when i tried another mp grids such as 4x4x4,
wannier would complain  " kmesh_get: something wrong, found > 12 nearest
neighbours"  and exit without generating tio2.nnkp data file.   would you
please  explain what the problem it is related to ?   From mannual , i guess
this error is due to kpoints' shell, but i donot follow much idea about this
setting, would you please explain more about it ?

Just with(4x4x2 mp mesh) , successfully finishing pw2wannier calculation ,
but wannier.x calculation gave this complain: "param_read: mismatch in
tita.eig"  .  Does it mean scf calculation is not converged or wrong
parameters for wannier.x ?

another stupid question about projection setting:    the setting Nicola gave
for PbTiO3 in last mail  is according its band's structure , and the
projection functions are s/p type-like orbitals.  i wanna know   whether
there are some guidelines for setting up initial projection functions ?

input file for tio2.win

num_wann  = 24
num_iter  = 400

begin atoms_cart
Ti       0.000000000  -0.946250000  -1.189250000
Ti       0.000000000   0.946250000   1.189250000
O        0.000000000   0.946250000  -0.796426921
O        0.000000000  -0.946250000   0.796426921
O        1.892500000   0.946250000   1.582073079
O       -1.892500000  -0.946250000  -1.582073079
end atoms_cart

begin projections
Ti:sp3
O : sp3
end projections

begin unit_cell_cart
bohr
          3.5763081161879673  -3.5763081161879673  8.9894295386987704
          3.5763081161879673   3.5763081161879673  8.9894295386987704
         -3.5763081161879673  -3.5763081161879673  8.9894295386987704
end unit_cell_cart
mp_grid : 4 4  2
  begin kpoints

  .............
 end kpoints

regards,
hai-ping
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