FIG. 7. Transposition along the 17 Å repeat axis of one Pad into two Cbs, as indicated by the lattice image shown in Fig. 5. (a) The correspondent chains of atoms in Pad and Cbs are shown using the structures of cuprobismutite (Ozawa and Nowacki, 1975) and padraite (Mumme, 1986). (b) Match between the DTD_Pad module and C_Cbs across the slicing shown in (a). The boundary between the two slabs is curved with maximum amplitude of 3 a_Cbs. L_c refers to CuBiS₁₀ lozenges attached to the C layer (see Fig. 1).