THE CRYSTAL-STRUCTURE OF THE MONOPHOSPHATE KSRPO4

Transparent crystals of KSrPO4 were grown from K2MoO4 flux by a slow c ooling method. They crystallize in the orthorhombic system with space group Pnma and lattice parameters : a = 7.352, b = 5.561, c = 9.642. A ngstrom, Z = 4. The crystal structure of the title compound, isotypic with those of KBaPO4 and RbBaPO4 (beta-K2SO4 type), was solved from 60 8 independent reflections with R = 0.039 (Rw = 0.026). It consists of independent [PO4] tetrahedra arranged in a way to delimit cavities of tenfold and ninefold coordination, occupied by K+ and Sr2+ respectivel y. The mean values P-O, K-O and Sr-O distances are equal to 1.538, 2.8 87 and 2.709 Angstrom respectively.