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oai:figshare.com:article/34020654 2026-09-29T03:13:30Z category_1 category_4 category_7 category_8 category_12 category_873 category_734 category_64 category_132 category_134 portal_63 item_type_6 month_year_09_2026

Revealing the Proton Slingshot Mechanism in Solid Acid Electrolytes through Machine-Learning Molecular Dynamics Menghang Wang (15261322) Jingxuan Ding (9332875) Grace Xiong (17880234) Ni Zhan (2744527) Cameron Owen (8934053) Albert Musaelian (9322335) Yu Xie (541970) Nicola Molinari (5184077) Ryan Adams (10766863) Boris Kozinsky (5070920) Sossina Haile (21389036) Biophysics Biochemistry Medicine Microbiology Cell Biology Chemical Sciences not elsewhere classified Biological Sciences not elsewhere classified Cancer Infectious Diseases Virology solid acid electrolytes network force fields greater rotational frustration local proton hopping learning molecular dynamics higher proton concentration fast proton conduction distinct proton concentrations proton slingshot mechanism 4 </ sub 2 </ sub limited polyanion rotation range transport arises proton transport range transport polyanion rotation slower dynamics proton coordination mechanism refines range jumps unique correlation type picture structural similarity rate process precise role oxygen sharing findings establish equivariant neural enhance conductivity conventional grotthuss attributed either In solid acid electrolytes CsH₂PO₄ and CsHSO₄, the origin of fast proton conduction has long been debated, attributed either to local proton hopping or to polyanion rotation. However, the precise role of polyanion rotation and its interplay with proton hopping remains unresolved. Nanosecond-scale molecular dynamics simulations, driven by equivariant neural-network force fields, reveal a nuanced proton slingshot mechanism: a rotating polyanion first carries the proton, O–H bond reorientation then extends its displacement, and the combined motion enables long-range jumps. This mechanism refines the conventional Grotthuss-type picture, revealing that long-range transport arises from significant O–H bond reorientation assisted by only limited polyanion rotation. Despite their structural similarity, CsH₂PO₄ and CsHSO₄ exhibit qualitatively different transport behavior associated with their distinct proton concentrations. In CsH₂PO₄, two rotation rates with different activation energies emerge, while CsHSO₄ displays a single-rate process with faster productive polyanion dynamics. The higher proton concentration in CsH₂PO₄ is associated with greater rotational frustration and slower dynamics of PO₄ compared with SO₄ in CsHSO₄. In CsH₂PO₄, we further identify a unique correlation between oxygen sharing and proton transport, arising from the extra proton per polyanion. Together, our findings establish a unified framework linking polyanion rotation, proton coordination, and long-range transport, and suggest that tuning proton concentration could accelerate rotation and enhance conductivity. 2026-09-28T00:00:00Z Text Journal contribution 10.1021/jacs.5c21965.s001 https://figshare.com/articles/journal_contribution/Revealing_the_Proton_Slingshot_Mechanism_in_Solid_Acid_Electrolytes_through_Machine-Learning_Molecular_Dynamics/34020654 CC BY-NC 4.0