A solid ammonia storage and delivery material A solid ammonia storage material comprising: an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula: Ma(NH3)nXz, wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and ri is the coordination number of 2 to 12, wherein M is Mg provides a safe, light-weight and cheap compact storage for ammonia to be used in the automotive industry.