[Pw_forum] polarization:5cells of pbtio3
Jaret Qi
jaretqi at yahoo.com
Sat Sep 5 16:07:42 CEST 2015
1.08277316 is c/a for pbtio3, I already did convergence test before run vc-relax, so what scf will add to my structure?
On Friday, September 4, 2015 6:45 PM, stefano de gironcoli <degironc at sissa.it> wrote:
the coordinates and the lattice vectors are given in unit of alat so you need
to add 1.08277316 x 1,2,3,4
where did you get 1.08 from?
In any case you need to run an scf calculation first.
stefano
On 05/09/2015 01:39, Jaret Qi wrote:
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?
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