The purpose of this an\u27d subsequent studies of the alkaline, thorium,
uranium (IV) or zirconium phosphates is to determine their crystal structures and so deduce the coordination number and polyhedron of the heavy atom. The common formula of these compounds is M 1M}V(PO ,L, where M 1 can be lithium, sodium, potassium, rubidium or cesium, and M 1V thorium, uranium {JV) or zirconium