enter image description hereDuring band structure calculations in Quantum espresso I found that the bands are coming in Linear form and not curvature. Why is this happening? Is there any explanation for this? Which parameters cause it and need correction?

Edit: I added a plot for reference.

  • $\begingroup$ You have to check the set of high symmetry points used (if they correspond to the cell used) and the defined path between them. $\endgroup$
    – Camps
    Sep 10, 2022 at 17:28
  • $\begingroup$ @Camps Sir, I am not talking about flat bands here. I am talking about bands coming in zig zag straight lines perpendicular to x axis. As I have understood that high symmetry points might cause this, I will check it out. $\endgroup$ Sep 10, 2022 at 18:17
  • $\begingroup$ @epsilon02fft you should upload an image $\endgroup$
    – Chan
    Sep 11, 2022 at 17:33
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    $\begingroup$ It would be very helpful to see a plot of the bandstructure, but the most common case where this happens is when you accidentally calculate the states on a 3D k-point grid, instead of along a 1D k-point path. When you plot it, you'll just get the states at disconnected points in k-space, which your plotting program will join up with straight lines. $\endgroup$ Sep 23, 2022 at 0:41
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    $\begingroup$ @PhilHasnip I have added the plot for reference. Thank you for your explanation. $\endgroup$ Oct 27, 2022 at 6:24