The structure ofBa7Cl2F12has been determinedab initiofrom conventional X-ray powder diffraction data by the “heavy atom” method. The cell is hexagonal (space groupP6¯,Z=1), witha=10.6373(2) Å andc=4.1724(2) Å. Refinement of 38 parameters by the Rietveld method, using 278 reflections, leads tocRwp=0.173,cRp=0.135, andRB=0.054. The structure has common characteristics with that of the otherBaF2-rich fluorochloride,Ba12Cl5F19. In both phasesBa2+ions lie in tricapped trigonal prisms formed by nine halide ions, andCl−ions occupy the center of trigonal prisms ofBa2+ions.F−ions are located in cationic tetrahedra or square pyramids.