Pariser–Parr–Pople for the win! A super-simple semi-empirical quantum chemical method built on top of the established Hückel method. Singlets, Triplets, Oh my!
[Bedogni2024] Bedogni, M., Giavazzi, D., Di Maiolo, F., Painelli, A. (2024). Shining Light on Inverted Singlet–Triplet Emitters. Journal of Chemical Theory and Computation, 20(2), 902–913. https://doi.org/10.1021/acs.jctc.3c01112
[DiMaiolo2023] Fortran code for the [Bedogni2024] paper. This code was validated against these outputs. https://github.com/francescodimaiolo/Hartree-Fock_PPP_tool
[Jorner2024] Jorner, K., Pollice, R., Lavigne, C., Aspuru-Guzik, A., 2024. Ultrafast Computational Screening of Molecules with Inverted Singlet–Triplet Energy Gaps Using the Pariser–Parr–Pople Semiempirical Quantum Chemistry Method. J. Phys. Chem. A 128, 2445–2456. https://doi.org/10.1021/acs.jpca.3c06357
[Ohno1964] Ohno, K. (1964). Some remarks on the Pariser-Parr-Pople method. Theoretica Chimica Acta, 2(3), 219–227. https://doi.org/10.1007/BF00528281
2024-- Jarvist Moore Frost
2025-- Freja Orritt
2025-- Abigail Levison
These codes were created with careful reference to [Bedogni2024] (non Beta-dependent Huckel/PPP model, and CIS/CISD etc. results), and then [Jorner2024] (Beta-dependent Huckel model).
The authors are grateful for useful discussions with Tim Hele and Kjell Jorner.