Rp. Bontchev et Sc. Sevov, CO5BP3O14 - THE FIRST BOROPHOSPHATE WITH PLANAR BO3 GROUPS CONNECTED TO PO4 TETRAHEDRA, Inorganic chemistry, 35(24), 1996, pp. 6910
The first example of a dimer of corner sharing BO3 and PO4 units, BPO6
4-, occurs in the title compound. The structure is built of layers of
such dimers separated by double layers of isolated PO4 tetrahedra. The
cobalt atoms are 6-, 5-, and 4-coordinated by the oxygen.