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k point length too high

Posted: Fri May 03, 2013 11:44 am
by MPis86
Dear Abinit users,

I want to calculate the band structure and wavefunctions in a BZ path with k-points having reduced coordinates exceeding 1.
When I do such calculation Abinit stops claiming that the reduced coordinates of kpoints must be between -1 and 1.
Is there a way to bypass this problem?

I know that I can use symmetry operations to take the point back inside the first BZ, unfortunately I want to avoid such procedure.

To be more specific
I want to calculate the band structure of graphene on Pt that have a 2x2 direct space supercell with respect to freestanding 1x1 graphene. Then I want to exclude the bands deriving from the folding of bands in the reduced BZ and compare the obtained band structure with the one of freestanding graphene.
I know that I can obtain only the "unfolded" bands by calculating the superposition of the 2x2 wavefunction with the 1x1 ones. So I have to calculate the band energies and wavefunctions on exactly the same k-points in both the 2x2 and the 1x1 calculations. However for the 2x2 calculation this implies that some kpoints have reduced coordinates exceeding 1.

Thanks in advance,
Michele

Re: k point length too high

Posted: Mon May 05, 2014 10:18 am
by Seba Darshan
hai

I am also doing band structure calculation on intrinsic undoped graphene.
I am now trying to study the adsorption of gas molecules on graphene supercell.
But I am not clear of how to define the unit cell of a 4 by 4 graphene supercell. Can you help me to create a 4 by 4 supercell.
How I need to define acell and rprim variables for creating a 4 by 4 supercell.

Regards
Seba