On 26/08/2024 03:58, Barry (Yangtao) Li wrote:
I am writing to seek your guidance on generating and properly gridding
complex-valued wavefunctions. Our goal is to obtain 3D complex
wavefunctions, fully gridded on their defined FFT grid, which we intend
to use for advanced spectroscopy simulations as an added feature to
Quantum Espresso.
"Fully gridded" = "on a real-space grid" or what else? There are 1001
places in QE where the wavefunctions are transformed from reciprocal
space (plane-wave components) to real space, or vice versa
Paolo
For instance, with a system defined by 2×2×2 k-points and no symmetry,
we expect to have 8 k-vectors (and therefore, we will obtain 8
wavefunctions binaries stored in .save after SCF). If we desire 40 bands
and an FFT grid of (20, 20, 20), our expectation is that 8 wavefunction
files (binaries or texts) would be written, each with the same size of
16×20×20×20×40 = 5,120.000 bytes as we are aiming for each wavefunction
to be stored as complex*16 data, separated by bands looping from 1 to
40, and in each band block its (1:20, 1:20, 1:20) a row of 3D complex
wavefunction data.
We would greatly appreciate any advice or documentation you can provide
on how to achieve this, especially how to ensure the wavefunctions are
accurately gridded on their FFT grid in the desired complex format, we
tried to count the bytes of the QE-generated .dat files, the bytes are
far away from the expected, so we don't know how to grid them. We also
tried pp.x postprocessing, however, since it is mainly designed for
orbital visualization, the phase information, i.e., the complex nature
of wavefunction is not stored after the post-processing. For Gamma-only,
we can do a square-root transformation, however, for non-Gamma cases,
the square-root won't work anymore.
We believe this capability could be highly beneficial for users
interested in extending QE's functionality into advanced spectroscopy,
and we would be more than happy to contribute to its development.
Thank you for your support and any assistance you can offer.
Sincerely
Barry
_______________________________________________
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
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--
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216
X SCUOLA ENERGIE RINNOVABILI 16-21/9/2024 - PRE-ISCRIZIONE
https://agenda.infn.it/event/39573/
_______________________________________________
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
