gamma-only calculation shows HOMO/LUMO at a different location of the 1st BZ?

[awang95]

Hi,

I did a static calculation of graphite at the gamma point, and when I tried to plot the wavefunctions of the HOMO and LUMO bands, I get the pi and pi*, which makes sense from a chemistry perspective. However, looking at the band structure of graphite (https://journals.aps.org/prb/pdf/10.110 ... .69.245419, Fig 2), at the gamma point the VBM and CBM are sigma-type, which makes me confused...if we're only doing the calculation at the gamma point how does it produce a HOMO and a LUMO that should be reflected at the M or L points of the 1st BZ?

Attached is also a figure to illustrate what I mean

thanks!

[pedro_melo]

Dear awang95,

Thank you for using VASP. However, as we do not provide support for scientific questions I have moved your question to the "From Users for Users" topic.

Do note that the Gamma only version projects your wave functions and Hamiltonian only at Gamma point. While it is good for molecules, for solids I would suggest to try the standard version of VASP and compare those results with literature.

Kind regards,
Pedro Melo