The title compounds were synthesized from Ln, LnX(3) (Ln = La, Ce; X = Cl, Br), and Sb under an Ar atmosphere at 950 ° C, They crystallize in the space group P6(3)/m (No. 176) with lattice constants a = 21.232(5) and 20.862(2) &ANGS; and c = 4.323(2) and 4,2728(7) &ANGS; for La9Sb16Br3 and Ce9Sb16Cl3, respectively. The solids are the most metal-rich members in the reduced rare earth metal halide family and contain partial structures which are characteristic of reduced halides and intermetallic phases. These are the [Ln(6)X(6)](∞) hexagon stars, Sb-centered [Ln(3)Sb](∞) trigonal prismatic columns, and stripes of Sb square meshes. Computational analysis indicates that their electronic structure is valence-precise in the reduced halide part, but electron-deficient in the intermetallic part. Susceptibility and resistivity measurements reveal the metallic nature of the compounds.