Zero Shift in Crispy
asked by Tim Burrow (2025/11/06 10:50)
Hi all,
A colleague of mine has recently approached me regarding the new file inputs generated by Crispy and we came across a new parameter.
Within these new inputs there is a “ZeroShift” parameter that was not previously used.
It seems that the value for this parameter is dependent on not only the element but also its oxidation state.
Ultimately, could somebody please clarify the origin of the values as we could not figure it out.
Many thanks as always, Tim
Answers
Hi Tim,
Yeah, this is poorly documented. You can find a description of the value here: https://github.com/mretegan/crispy/blob/v0.8.0/src/crispy/quanty/axes.py#L319
As you know, the spectra in Quanty are not aligned with the experimental ones. If you do an L2,3 calculation, the two edges will be split around zero by a value dependent on the spin-orbit coupling (mostly). The zero shift should approximately align the L3 edge to zero. The value is the same for an element regardless of the oxidation state.
Then you have a tabulated value that further shifts the spectra to bring it in the experimental range.
Don't hesitate to let me know if there are issues with this.
Cheers, Marius