Reactive deposition epitaxy growth of calciumgermanosilicides Ca(Si1-xGex)(2) with 0 less than or equal tox less than or equal to1 is described, starting from epitaxial Si1-xGex films on Si(1 1 1) as well as pure Si(1 1 1) and Ge(1 1 1) as substrate material. The Ge content x of the Ca(Si1-xGex)(2) films formed is identical to that of the original Si1-xGex films within experimental accuracy. Ca(Si1-xGex)(2) Zintl-phases show a trigonal rhombohedral crystal structure with a tr6 stacking sequence. While the c lattice constant is 30.6 Angstrom independent of the Ge content. the a lattice constant increases linearly with a from a = 3.855 Angstrom for CaSi2 to a = 4.01 Angstrom for CaGe2. Ca(Si1-xGex,)(2) is found to be unstable in ambient atmosphere and decomposes typically within some minutes.