Proton Ordering Induces a Polar Structure in the Antiferromagnetic Solid Proton Conductor FeH6(PO4)3 - Lara M. Gronych; Marvin A. Kraft; Matthias Hartmann; Vasiliki Faka; Dana Glikman; Iven Koers; Cheng Li; Jon Newnham; Björn Braunschweig; Wolfgang G. Zeier; Xabier Martinez de Irujo-Labalde (Journal of the American Chemical Society, 2025)