sentences:  Zintl phases can incorporate hydrogen.Such Zintl phase hydrides«ref name="HäussermannKranak2010"> can be either formed by direct synthesis of the elements or element hydrides in a hydrogen atmosphere or by a hydrogenation reaction of a pristine Zintl phase.Since Hydrogen has a comparable electronegativity as the post-transition metal it is incorporated as part of the polyanionic patial structure.