[QE-users] R: one question about the matrix element calculation

[Pietro Davide Delugas]

Hi there,

The data in p_avg.dat are k-resolved, which means that point-wise, the symmetries are limited to the small group of rotations that preserve the specific k-point. However, you can still compare the matrix elements at two corresponding rotated k-points.

If your bands are degenerate due to symmetry, it is also necessary to compare the correct corresponding partners of the occupied and unoccupied irreducible representations.

Hope it helps
Pietro
________________________________
Da: users <users-bounces at lists.quantum-espresso.org> per conto di Yu, Jingjing <jy95vowa at studserv.uni-leipzig.de>
Inviato: domenica 17 settembre 2023 19:01
A: users at lists.quantum-espresso.org <users at lists.quantum-espresso.org>
Oggetto: [QE-users] one question about the matrix element calculation

Dear QE community members,

I am a beginner to do the DFT calculation. I have one question regarding
to extracting matrix elements of the momentum operator between the
valence and conduction bands wrriten in the file of "p_avg.dat".

I am wondering if the corresponding matrix elements along the x, y, z
directions should be that same if the crystal structure of material is
cubic (isotropic)?

Thanks a lot!

Best regards,
Jingjing Yu

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