0.95 Ag 1.05 Ge 5 is synthesized by solid state reaction of the elements in the atomic ratio Ca:Mg:Ag:Ge = 3:1:1:2 (Nb/Ta tube, Ar atmosphere, 870 C, 5 d). The compound crystallizes in the orthorhombic space group Pnma with Z = 4. The crystal structure is a linear intergrowth of slabs cut from the CaGe (CrB-type) and the CaMGe (TiNiSi-type; M: Mg, Ag) structures. Hence, the compound is a hettotype of the hitherto missing n = 3 member of the R 2+n T 2 X 2+n structure series. The compound is deficient by one valence electron according to the Zintl concept, but LMTO electronic structure calculations indicate electronic stabilization and overall bonding optimization in the polyanionic network. -(PONOU*, S.; LIDIN, S.; ZHANG, Y.; MILLER, G. J.; Inorg. Chem. 53 (2014) 9, 4724-4732, http://dx.