PREPARATION AND CRYSTAL-STRUCTURE OF A NEW ACENTRIC CESIUM GALLIUM HYDROGEN PHOSPHATE-CONTAINING PHOSPHORIC-ACID, 2PO4)(HPO4)(2)CENTER-DOT-H3PO4-CENTER-DOT-0.5H(2)O

Single crystals of caesium gallium hydrogen phosphate, CS2Ga(H2PO4)(HP O4)(2) . H3PO4 . 0.5H(2)O, were prepared by microwave-induced heating (1 h) a mixture of CsGa(H2PO4)(4) and CS2CO3 in the excess of H3PO4. I t crystallizes tetragonal, space group I4(1)cd (N degrees 110 Int. Tab .) with Z = 16 and a = 2016.8(5), c = 1828.7(5) pm. The crystal struct ure was solved by using 3341 unique reflections Fo > 4 sigma (Fo) with a final wR2 value of 0.1549 (SHELXL-93). The main feature of the crys tal structure are columns formed by PO4-tetrahedra around the GaO6 oct ahedra along the [001] direction. Cs+, H3PO4 and H2O molecules connect the columns into framework. Effective Coordination Numbers (ECoN), Me an Fictive Ionic Radii (MEFIR), Charge Distribution (CHARDI) and the M adelung Part of Lattice Energy (MAPLE) are calculated for the title co mpound.