Calcium nitride is the inorganic compound with the chemical formula Ca<sub>3</sub>N<sub>2</sub>. It exists in various forms (isomorphs), ñ-calcium nitride being more commonly encountered.
ñ-Calcium nitride adopts an anti-bixbyite structure, similar to Mn<sub>2</sub>O<sub>3</sub>, except that the positions of the ions are reversed: calcium (Ca<sup>2+</sup>) take the oxide (O<sup>2âÂÂ</sup>) positions and nitride ions (N<sup>3âÂÂ</sup>) the manganese (Mn<sup>3+</sup>). In this structure, Ca<sup>2+</sup> occupies tetrahedral sites, and the nitride centres occupy two different types of octahedral sites.
Calcium nitride is formed along with the oxide, CaO, when calcium burns in air. It can be produced by direct reaction of the elements:
It reacts with water or even the moisture in air to give ammonia and calcium hydroxide:
Like sodium oxide, calcium nitride absorbs hydrogen above 350 ðC: