An electron spin resonance study was made of mixed crystals of the form, (Rb0.9(NH4)0.1)2AgI3, which had been irradiated at 77K. It was deduced that I2- was situated on the horizontal edge of I tetrahedrons that were linked together parallel to the b-axis. It was noted that I0 was located on one of the I ions on the horizontal edge of the I tetrahedron, and was slightly displaced towards one of the nearby NH4 ions. Their hyperfine parameters were essentially the same as those for the end-members of the solid solution.

T.Awano, T.Matsuyama: Radiation Effects and Defects in Solids, 1995, 134, 389-93