This folder contains the data from the publication "Exploring energy landscapes of charge multipoles using constrained density functional theory" by Luca Schaufelberger, Maximilian E. Merkel, Aria Mansouri Tehrani, Nicola A. Spaldin, and Claude Ederer published in Phys. Rev. Research in 2023, doi.org/10.1103/PhysRevResearch.5.033172.
To rerun the notebooks for data evaluation and plotting, you first need to get multipyles v1.1.0 from [GitHub](https://github.com/materialstheory/multipyles/tree/v1.1.0) or from the corresponding [Zenodo repository](doi.org/10.5281/zenodo.8199391). Within the notebooks, you then need to modify `sys.path.append('/home/mmerkel/Programs/multipyles')` to contain your own path to multipyles.
All pickle files (`*.pkl`) in the folders are just used for easier exchange of data between the notebooks and are automatically written and read when running the notebooks.
For the VASP calculations with constrained multipoles, please apply the patch files available on the GitHub repository linked above. Note that the there is a small difference in the DFT energy (as for example written to the OUTCAR) between the data here and what the patched VASP now produces.
While the VASP diff files on GitHub now produce the correct final energy as defined in Eq. (7), the present data in this Materials Cloud Archive was generated with a previous version where the energy from DFT still needed to be corrected by Eq. (10) in the notebooks (all equations refer to our publication).
Therefore, if you now rerun the calculations with the patch files on GitHub, the energy corrections proportional to w_kt^I s_kt^I inside the jupyter notebooks (such as `correction_AF` in fig3.ipynb) will not be necessary anymore.
Folder fig4 also contains the charge density `CHGCAR_for_restart` that is the starting point for all restart calculations in `fig4/` and that is generated by the run with a small, positive shift in `shiftUDiffMagOrder2-0.2-AFG-AFGM`, as also described in the publication.
Finally, we have used the following POTCARs:
- K : PAW_PBE K_pv 17Jan2003 (VRHFIN =K: p6s1)
- Cu: PAW_PBE Cu 22Jun2005 (VRHFIN =Cu: d10 p1)
- Zn: PAW_PBE Zn 06Sep2000 (VRHFIN =Zn: d10 p2)
- F : PAW_PBE F 08Apr2002 (VRHFIN =F: s2p5)