In chemistry a Zintl phase is the product of a reaction between a group 1 (alkali metal) or group 2 (alkaline earth) and any post transition metal or metalloid (i.e. from group 13, 14, 15 or 16). They are named for the German chemist Eduard Zintl who investigated them in the 1930s, with the term "Zintl Phases" was first used by Laves in 1941.