The title compounds were obtained in high yields as pale yellow, transparent crystals after reacting appropriate mixtures of CsBr, NaBr, LaBr3, and LaN in sealed Ta tubing at 850 degrees C for 20 d. The structures have been established by single-crystal X-ray diffraction techniques and powder diffraction. CsNaLa6Br14N2 forms a new structure type in the monoclinic space group P2(1)/n with the lattice parameters a = 10.452(1) Angstrom, b = 13.193(2) Angstrom, c = 10.876(2) Angstrom, beta = 95.07(1)degrees, and Z = 2. La3Br6N is isotypic to Ce3Br6N and crystallizes in the orthorhombic space group Pbca with a = 11.212(1) Angstrom, b = 11.828(1) Angstrom, c 17.176(1) Angstrom, and Z = 4. The significant structural features of both compounds are pairs of rare-earth-metal tetrahedra that are each centered by N and share a common edge to form La6N2 bitetrahedral units. These are surrounded and interbridged by Br atoms to form a three-dimensional network. Ln the case of CsNaLa6Br14N2 the Cs and Na atoms are located in bromine-lined cuboctahedral and octahedral cavities, respectively. Although "normal-valent" salts, the structures of the new nitride halides are geometrically closely related to the metal-rich cluster compounds such as Cs2La10I17Co2 with bioctahedral La-10 units that are centered by the transition-metal atoms. Calculations of the Madelung part of lattice energy, MAPLE, illustrate the close relationship of the two structures.