Hypophosphite hybrid perovskites: a platform for unconventional tilts and shifts.

Following the recent discovery of the [A]Mn(H2POO)3 (H2POO- = hypophosphite) perovskite family, we report the A = [NH2(CH3)2]+ (dimethylammonium, DMA) member. This phase shows an unusually large unit cell due to the position of the A-site cation within the perovskite cage windows rather than the centre, as is the norm. We discuss the tendency of the hypophosphite perovskite skeleton to accommodate differently shaped A-site cations through the generation of unconventional tilts and columnar shifts, then enumerate these tilts and shifts for all known [A]Mn(H2POO)3 phases.