The crystal structure of Ca 12 Al 14 O 32 Cl 2 was determined from laboratory X-ray powder diffraction data (CuKa 1 ) using the Rietveld method, with the anisotropic displacement parameters being assigned for all atoms. The crystal structure is cubic (space group I 43d, Z ΒΌ 2) with lattice dimensions a ΒΌ 1.200950(5) nm and V ΒΌ 1.73211(1) nm 3 . The reliability indices calculated from the Rietveld method were R wp ΒΌ 8.48% (S ΒΌ 1.21), R p ΒΌ 6.05%, R B ΒΌ 1.27% and R F ΒΌ 1.01%. The validity of the structural model was verified by the threedimensional electron density distribution, the structural bias of which was reduced as much as possible using the maximum-entropy methods-based pattern fitting (MPF). The reliability indices calculated from the MPF were R B ΒΌ 0.75% and R F ΒΌ 0.56%. In the structural model there are one Ca site, two Al sites, two O sites and one Cl site. This compound is isomorphous with Ca 12 Al 10.6 Si 3.4 O 32 Cl 5.4 . Europium-doped sample Ca 12 Al 14 O 32 Cl 2 :Eu 2+ was prepared and the photoluminescence properties were presented. The excitation spectrum consisted of two wide bands, which were located at about 268 and 324 nm. The emission spectrum, when excited at 324 nm, resulted in indigo light with a peak at about 442 nm.