============================================
Parametrization for metal halide perovskites
============================================

(c) 2017, Marcus Elstner, Karlsruher Institut für Technologie
[original mio set]

(c) 2024, Junke Jiang, INSA Rennes
[extension with I, Cs, Pb, recalculating all tables for consistency]

(c) 2026, Junke Jiang, INSA Rennes
[extension with Br; F retained from pbc-0-3 and S from mio-1-1]

All rights reserved

This work is licensed under the Creative Commons Attribution-ShareAlike 4.0
International License. To view a copy of this license, consult the LICENSE file
or visit http://creativecommons.org/licenses/by-sa/4.0/ .

NOTE: The rights holder(s) for this work explicitly require that the attribution
conditions of this license are enforced. Use in part or in whole of this data is
permitted only under the condition that the scientific background of the
Licensed Material will be CITED IN ANY PUBLICATIONS ARISING FROM ITS USE. The
required references are specified in this file and must be included in resulting
works.


General information
===================

This set was designed to describe the electronic structure of 2D and 3D metal
halide perovskites. The parameters of H, C, and N may slightly deviate from mio-1-1.
We refer to the detailed documentation in the Slater-Koster files for further
information. The compression radii of Cs have been taken from Ref.[JCTC13], the
power of the confinement potential, however, is slightly different.
The public set contains H, C, N, F, S, Cs, Br, I, and Pb.
For perov-1-1, H, C, N, Cs, Pb, and I parameters are retained from
perov-1-0, S parameters from mio-1-1, and F parameters from pbc-0-3.

Note: This set assumes that you use shell-resolved SCC in DFTB. In case you use
the DFTB+ code, you can achieve it by setting `OrbitalResolvedSCC = Yes`.


Maximal angular momenta
-----------------------
H: s
C: p
N: p
F: p
S: d
Br: p
I: p
Cs: s
Pb: p


Spin constants
--------------

Note, the calculation of the spin constants follows here for all elements the
convention as used for the Hubbard U values: For non-occupied atomic orbitals
(orbitals above HOMO), the corresponding value of the HOMO is used.

H:
     -0.07174
C:
     -0.03062     -0.02505
     -0.02505     -0.02265
N:
     -0.03318     -0.02755
     -0.02755     -0.02545
F:
     -0.03698     -0.03124
     -0.03124     -0.02990
S:
     -0.02137     -0.01699     -0.01699
     -0.01699     -0.01549     -0.01549
     -0.01699     -0.01549     -0.01549
Cs:
     -0.00949
Br:
     -0.01839     -0.01435
     -0.01435     -0.01376
I:
     -0.01445     -0.01132
     -0.01132     -0.01145
Pb:
     -0.01335     -0.00932
     -0.00932     -0.01097


Repulsive energy:
========================================

NOTABENE: NO REPULSIVE potential is provided; there is a dummy spline only.
          The SKFs CANNOT be used to do structural relaxation.


Relevant publications
=====================
[JCP26] J. Jiang et al., J. Chem. Phys. (2026), in peer review.

[PRMat25] J. Jiang et al., Phys. Rev. Materials 9, 023803 (2025).

[JCTC13] M. Wahiduzzaman et al., J. Chem. Theory Comput. 9, 9, 4006 (2013).

[SurfSci06] C. Koehler et al., Surf. Sci., 600, 453, (2006). 

[PRB98] M. Elstner, D. Porezag, G. Jungnickel, J. Elsner, M. Haugk,
Th. Frauenheim, S. Suhai, and G. Seifert, Phys. Rev. B 58, 7260 (1998).


Required references
===================

H,C,N,S - H,C,N,S:             [PRMat25,JCP26,PRB98]
H,C,N,F,S,Cs,Br,I,Pb - F:      [SurfSci06]
H,C,N,F,S,Cs,Br,I,Pb - Br:     [JCP26]
H,C,N,F,S,Cs,Br,I,Pb - I:      [PRMat25]
H,C,N,F,S,Cs,Br,I,Pb - Cs:     [PRMat25,JCTC13]
H,C,N,F,S,Cs,Br,I,Pb - Pb:     [PRMat25]