Cover illustration: Two-dimensional isostructurality among polymorphs of benzene-1,2-diamine, showing (top) the crystal packing in one polymorph, viewed down the a axis, and (bottom) the crystal packing in a second polymorph, viewed down the b axis. Hydrogen bonds are shown as dotted lines. See Czapik & Gdaniec [Acta Cryst. (2010), C66, o198-o201].
In Sr2.88Cu3.12(PO4)4, the special Sr1 site (2b, site symmetry ) is occupied by 0.88 (3) Sr and 0.12 (3) Cu, while Sr2 cations partially occupy two positions denoted as Sr2a and Sr2b, separated by a distance of 0.48 (3) Å. The Sr cations are situated between layers formed by the connection of Cu atoms by PO4 tetrahedra.