Publisher Summary This chapter presents a summary on the various structural motifs documented for halogenocuprate(I) and halogenoargentate(I) ions in the solid state, placing special emphasis on the variations in the coordination number of the metal. Anionic configurations in crystalline halogenocuprates(I) and halogenoargentates(I) appear to be strongly dependent on the nature of the cation, thus permitting, in principle, the preparation of a species, containing copper(1) or silver(I), with a desired coordination number by pertinent choice of cation. The interpretation and correlation of spectroscopic properties, in the context of structure and bonding, for compounds of group IB and group IIB metals, have been discussed in the chapter. Solid-state structures documented hitherto for halogenocuprate(I) and halogenoargentate(I) ions are described in the order of increasing coordination number of the metal. Possible correlations between the coordination number of copper(I) or silver(I) in the anion and properties of the cation with which it is coprecipitated, such as size, shape, and exposure of the positive charge, are also discussed. The most widespread method of preparation is reaction between the metal(I) halide and the halide salt of the appropriate cation dissolved in an organic solvent.