[Pw_forum] polarization:5cells of pbtio3

[Jaret Qi]

Hello all,I'm calculating the polarization of 5 cells of PbTiO3, I have set up the one unit cell correctly and got all of the properties in a good agreement as in literature. But when I tried to calculate the polarization of the 5 cells, I got this error when I run the nscf:error: too many bands are not converged,The way I constructed the 5 cells is by adding c/a for the z-components of the 2nd cell, 2c/a for the z-components of the 3rd cell, 3c/z for the z-components of the 4th cell, 4c/a for the z-components of the 5th cell.
see this:1cell :
ATOMIC_POSITIONS 
Pb       0.000000000   0.000000000  -0.011923470
Ti       0.498189800   0.498189800   0.542939650
O        0.498189800   0.498189800   0.085663538
O        0.498189800   0.000000000   0.642799807
O        0.000000000   0.498189800   0.642799807

CELL_PARAMETERS (alat)
   0.996379599   0.000000000   0.000000000
   0.000000000   0.996379599   0.000000000
   0.000000000   0.000000000   1.082777316

5cells:
ATOMIC_POSITIONS  
Pb      0.0000000       0.0000000      -0.01192347
Ti      0.4981898       0.4981898       0.54293965
O       0.4981898       0.4981898       0.085663538
O       0.4981898       0.0000000       0.642799807
O       0.0000000       0.4981898       0.642799807
Pb      0.0000000       0.0000000       1.06807653
Ti      0.4981898       0.4981898       1.62293965
O       0.4981898       0.4981898       1.165663538
O       0.4981898       0.0000000       1.722799807
O       0.0000000       0.4981898       1.722799807
Pb      0.0000000       0.0000000       2.14807653
Ti      0.4981898       0.4981898       2.70293965
O       0.4981898       0.4981898       2.245663538
O       0.4981898       0.0000000       2.802799807
O       0.0000000       0.4981898       2.802799807
Pb      0.0000000       0.0000000       3.22807653
Ti      0.4981898       0.4981898       3.78293965
O       0.4981898       0.4981898       3.325663538
O       0.4981898       0.0000000       3.882799807
O       0.0000000       0.4981898       3.882799807
Pb      0.0000000       0.0000000       4.30807653
Ti      0.4981898       0.4981898       4.86293965
O       0.4981898       0.4981898       4.405663538
O       0.4981898       0.0000000       4.962799807
O       0.0000000       0.4981898       4.962799807
CELL_PARAMETERS (alat)
   0.996379599   0.000000000   0.000000000
   0.000000000   0.996379599   0.000000000
   0.000000000   0.000000000   5.413886650

Is there any problems with the construction of the supercell?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20150904/d12273ae/attachment.html>