Citation: Schmitt, Tanja; Bourelle, Sean; Tye, Nathaniel; Soavi, Giancarlo; Bond, Andrew D.; Feldmann, Sascha; Traore, Boubacar; Katan, Claudine; Even, Jacky; Dutton, Si\^an E; Deschler, Felix (2020). Control of crystal symmetry breaking with halogen substituted benzylammonium in layered hybrid metal-halide perovskites.. Journal of the American Chemical Society, , pp. -.