eprintid: 10204490 rev_number: 9 eprint_status: archive userid: 699 dir: disk0/10/20/44/90 datestamp: 2025-02-11 13:17:33 lastmod: 2025-02-11 13:17:33 status_changed: 2025-02-11 13:17:33 type: article metadata_visibility: show sword_depositor: 699 creators_name: Li, Zhendong creators_name: Hernández, Federico J creators_name: Salguero, Christian creators_name: Lopez, Steven A creators_name: Crespo-Otero, Rachel creators_name: Li, Jingbai title: Machine learning photodynamics decode multiple singlet fission channels in pentacene crystal ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F56 note: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. abstract: Crystalline pentacene is a model solid-state light-harvesting material because its quantum efficiencies exceed 100% via ultrafast singlet fission. The singlet fission mechanism in pentacene crystals is disputed due to insufficient electronic information in time-resolved experiments and intractable quantum mechanical calculations for simulating realistic crystal dynamics. Here we combine a multiscale multiconfigurational approach and machine learning photodynamics to understand competing singlet fission mechanisms in crystalline pentacene. Our simulations reveal coexisting charge-transfer-mediated and coherent mechanisms via the competing channels in the herringbone and parallel dimers. The predicted singlet fission time constants (61 and 33 fs) are in excellent agreement with experiments (78 and 35 fs). The trajectories highlight the essential role of intermolecular stretching between monomers in generating the multi-exciton state and explain the anisotropic phenomenon. The machine-learning-photodynamics resolved the elusive interplay between electronic structure and vibrational relations, enabling fully atomistic excited-state dynamics with multiconfigurational quantum mechanical quality for crystalline pentacene. date: 2025-01-30 date_type: published publisher: Springer Science and Business Media LLC official_url: https://doi.org/10.1038/s41467-025-56480-y oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2357500 doi: 10.1038/s41467-025-56480-y medium: Electronic pii: 10.1038/s41467-025-56480-y lyricists_name: Crespo Otero, Rachel lyricists_id: RCRES48 actors_name: Crespo Otero, Rachel actors_id: RCRES48 actors_role: owner funding_acknowledgements: 22303053 [National Natural Science Foundation of China (National Science Foundation of China)]; NSF-CHE-2144556 [National Science Foundation (NSF)]; G00006360 [Massachusetts Life Sciences Center (MLSC)]; RPG-2019-122 [Leverhulme Trust]; EP/R029385/1 [RCUK | Engineering and Physical Sciences Research Council (EPSRC)]; IES\R2\222057 [Royal Society] full_text_status: public publication: Nature Communications volume: 16 article_number: 1194 event_location: England issn: 2041-1723 citation: Li, Zhendong; Hernández, Federico J; Salguero, Christian; Lopez, Steven A; Crespo-Otero, Rachel; Li, Jingbai; (2025) Machine learning photodynamics decode multiple singlet fission channels in pentacene crystal. Nature Communications , 16 , Article 1194. 10.1038/s41467-025-56480-y <https://doi.org/10.1038/s41467-025-56480-y>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10204490/1/Crespo%20Otero_s41467-025-56480-y.pdf