Inorganic metal azide salts are characterized by a broad range of physical and chemical properties due to their composilion of spherical cations and dumbbell shaped molecular azide anions N~. The most striking feature in this respect is the strongly changing explosive nature according to the type of cation present in the crystal, the geometric and electronic structure, and the various kinds of possible non-spherical charge distributions causing less or more covalent bonding within a predominantly ionic lattice, respectively. Despite the many solid state studies of inorganic azides (I, 2, 3, 4) in order to correlate stability and/or sensitivity with structural aspects it is remarkable that a systematic investigation of magnetic properties is lacking. It is the purpose of a research project to fill this gap. In this work, we present diamagnetic susceptibilities of microcrystalline azides MN 3 with M = Li,Na,K,Rb,Cs,NH4,T1 at 296 K. The crystal structures that are derivable from those of the corresponding halides reveal in the N~ sublattices layers with different relative orientations of the linear symmetrical triatomic nitrogen chain. Therefore, differences in the interaction of the metal ~ad azide ions make these compounds in our view candidates for both a rediscussion and improvement of the often used magnetic additiv~ty rules (5) for chemical applications of diamagnetic data.