Single-crystal growth and structure determination of Ag16I12P2O7

Single crystals of the fast-ion conductor Ag16I12P2O7 were prepared and their structure (P6mcc, a = 12.054, c = 7.504 Å) was determined by X-ray diffraction (r = 0.08). The I atoms form a close-packed array leaving channels occupied by P2O4−7 ions running along the c axis. The Ag atoms are disordered over four different types of site with occupation numbers ranging from 0.12 to 0.52. Each Ag+ ion coordination polyhedron shares several faces with adjacent polyhedra providing ready paths for Ag+ ion conduction.