Figure 3

Polyhedral (upper) and ball-and-stick (middle) model views of o-CD₃ND₃PbI₃ (10 K) from powder neutron diffraction data³². The distances marked a, b in blue and c, d in green in (a) through (c) distinguish between the potential I···D–C and I···D–N deuterium bonds. The a and d labels are repeated for equivalent bonds. Similar hydrogen bonded contacts are identifiable in the structure reported for crystal data of o-CH₃NH₃PbI₃³¹, although with somewhat different intermolecular distances (Fig. 2). Shown in (a–d) are the CD₃ND₃⁺···^-I₃Pb molecular blocks extracted from the polymorph B) (see text for detail).