Citation: Mencel, K.; Starynowicz, P.; Siczek, M.; Piecha-Bisiorek, A; Jakubas, R.; Medycki, W. (2019). Symmetry breaking structural phase transitions, dielectric properties and molecular motions of formamidinium cations in 1D and 2D hybrid compounds: (NH2CHNH2)3[Bi2Cl9] and (NH2CHNH2)3[Bi2Br9].. Dalton transactions (Cambridge, England : 2003), 48, pp. 14829-14838.