Germanane is a single-layer crystal composed of germanium with one hydrogen bonded in the z-direction for each atom. Germanane's structure is similar to graphane, Bulk germanium does not adopt this structure. Germanane is produced in a two-step route starting with calcium germanide. From this material, the calcium (Ca) is removed by de- intercalation with HCl to give a layered solid with the empirical formula GeH. The Ca sites in Zintl-phase CaGe 2 interchange with the hydrogen atoms in the HCl solution, producing GeH and CaCl 2.