Four new compounds were found in the system SmF 2SmF 3: Sm 3F 7, Sm 14F 33, Sm 27F 64, and Sm 13F 32-δ. These anion-excess, fluorite-related superstructure phases are members of the homologous series Sm mF 2 m+5 with m = 15, 14, and 13. Sm 27F 64 is a combination of the members with m = 14 and m = 13. Sm 13F 32-δ is isostructural with Na 7Zr 6F 31+□. X-ray powder patterns and lattice parameters of all phases are reported.