TbGa2.64(4)Sn0.36(4) - A new close-packed structure type

► TbGa2.64Sn0.36 represents a new close-packed structure type. ► The structure is built from 18 monoatomic layers with triangular mesh. ► Triangular-mesh layers are stacked along [0 0 1] in the sequence cchhcccchhcccchhcc. ► TbGa2.64Sn0.36 structure characterizes by partial ordering of Ga and Sn atoms. ► Hexagonality of the structures decrease at the Sn content increase in TbGa3−xSnx.