EIGENVAL file kpoint coordinates not matching KPOINTS file
Posted: Sat Aug 28, 2010 8:51 am
I have written the following Kpoints file (having followed the VASP manual instructions) in order to draw the band structure for a graphene like hexagonal lattice:
k-points along high symmetry lines
20
Line-mode
cart
.768559052642 .4437277775931 0
0 0 0
0 0 0
.512372701761 .887455551861 0
I have been very carefull to calculate those three coordinates (M, Gamma, and K points for a 2D hexagonal gallium phosphide lattice) and I am confident that they are correct.
But when I try to plot the bands from the EIGENVAL folder, I get a band structure that's obviously wrong. After closer examination of the EIGENVAL folder, I noticed that the kpoint coordinates listed above the energies for each kpoint have nothing to do with the coordinates I put into KPOINTS file (and yes, the coords in the EIGENVAL file are in cartesian coords). There are 20 points along each line, but the lines aren't between M-Gamma-K like I defined them to be. Here's a list of the kpoint coordinates pulled from the eigenval folder:
-5.88E-09 3.14E+00
-5.58E-09 2.98E+00
-5.27E-09 2.81E+00
-4.96E-09 2.65E+00
-4.65E-09 2.48E+00
-4.34E-09 2.31E+00
-4.03E-09 2.15E+00
-3.72E-09 1.98E+00
-3.41E-09 1.82E+00
-3.10E-09 1.65E+00
-2.79E-09 1.49E+00
-2.48E-09 1.32E+00
-2.17E-09 1.16E+00
-1.86E-09 9.92E-01
-1.55E-09 8.27E-01
-1.24E-09 6.61E-01
-9.29E-10 4.96E-01
-6.19E-10 3.31E-01
-3.10E-10 1.65E-01
8.27E-25 0.00E+00
0.00E+00 0.00E+00
-1.10E-01 1.10E-01
-2.20E-01 2.20E-01
-3.31E-01 3.31E-01
-4.41E-01 4.41E-01
-5.51E-01 5.51E-01
-6.61E-01 6.61E-01
-7.72E-01 7.72E-01
-8.82E-01 8.82E-01
-9.92E-01 9.92E-01
-1.10E+00 1.10E+00
-1.21E+00 1.21E+00
-1.32E+00 1.32E+00
-1.43E+00 1.43E+00
-1.54E+00 1.54E+00
-1.65E+00 1.65E+00
-1.76E+00 1.76E+00
-1.87E+00 1.87E+00
-1.98E+00 1.98E+00
-2.09E+00 2.09E+00
which are just not along the directions between the K - Gamma - M points that I speciafied in the KPOINTS file.
I first relaxed the lattice, then ran a static selfconsistent run, then ran this third non-selfconsistent run with icharge=11 just like the manual says. I have had success using this method to study nanotubes, so I'm confident about the procedure.
Has anyone run into this problem or know what I might be doing wrong?
<span class='smallblacktext'>[ Edited ]</span>
k-points along high symmetry lines
20
Line-mode
cart
.768559052642 .4437277775931 0
0 0 0
0 0 0
.512372701761 .887455551861 0
I have been very carefull to calculate those three coordinates (M, Gamma, and K points for a 2D hexagonal gallium phosphide lattice) and I am confident that they are correct.
But when I try to plot the bands from the EIGENVAL folder, I get a band structure that's obviously wrong. After closer examination of the EIGENVAL folder, I noticed that the kpoint coordinates listed above the energies for each kpoint have nothing to do with the coordinates I put into KPOINTS file (and yes, the coords in the EIGENVAL file are in cartesian coords). There are 20 points along each line, but the lines aren't between M-Gamma-K like I defined them to be. Here's a list of the kpoint coordinates pulled from the eigenval folder:
-5.88E-09 3.14E+00
-5.58E-09 2.98E+00
-5.27E-09 2.81E+00
-4.96E-09 2.65E+00
-4.65E-09 2.48E+00
-4.34E-09 2.31E+00
-4.03E-09 2.15E+00
-3.72E-09 1.98E+00
-3.41E-09 1.82E+00
-3.10E-09 1.65E+00
-2.79E-09 1.49E+00
-2.48E-09 1.32E+00
-2.17E-09 1.16E+00
-1.86E-09 9.92E-01
-1.55E-09 8.27E-01
-1.24E-09 6.61E-01
-9.29E-10 4.96E-01
-6.19E-10 3.31E-01
-3.10E-10 1.65E-01
8.27E-25 0.00E+00
0.00E+00 0.00E+00
-1.10E-01 1.10E-01
-2.20E-01 2.20E-01
-3.31E-01 3.31E-01
-4.41E-01 4.41E-01
-5.51E-01 5.51E-01
-6.61E-01 6.61E-01
-7.72E-01 7.72E-01
-8.82E-01 8.82E-01
-9.92E-01 9.92E-01
-1.10E+00 1.10E+00
-1.21E+00 1.21E+00
-1.32E+00 1.32E+00
-1.43E+00 1.43E+00
-1.54E+00 1.54E+00
-1.65E+00 1.65E+00
-1.76E+00 1.76E+00
-1.87E+00 1.87E+00
-1.98E+00 1.98E+00
-2.09E+00 2.09E+00
which are just not along the directions between the K - Gamma - M points that I speciafied in the KPOINTS file.
I first relaxed the lattice, then ran a static selfconsistent run, then ran this third non-selfconsistent run with icharge=11 just like the manual says. I have had success using this method to study nanotubes, so I'm confident about the procedure.
Has anyone run into this problem or know what I might be doing wrong?
<span class='smallblacktext'>[ Edited ]</span>