A novel lithium copper iron phosphate with idealized formula Li(5)Cu(2) (2+)Fe(3+)(PO(4))(4): crystal structure and distribution of defects

Gray–green single crystals were obtained under high-pressure, high-temperature hydro­thermal conditions. A refinement of atom occupancies gave the composition Li(3.68)Cu(2+)Fe(3+)(Cu(0.55)Li(0.45))(2)Fe(2+) (0.15)(PO(4))(4). The structure is built from triplets of edge-sharing (Cu,Li)O(5)–FeO(6)–(Cu,Li)O(5) polyhedra, CuO(4) quadrilaterals and PO(4) tetra­hedra. In the (Cu,Li)O(5) polyhedra the Cu and Li positions are statistically occupied in a 0.551 (2):0.449 (2) ratio. Both FeO(6) and CuO(4) polyhedra exhibit [Image: see text] symmetry. The positions of additional Li atoms with vacancy defects are in the inter­stices of the framework.