A new ternary compound of composition (V,Mo)84P49 (V3.2Mo8.8P7) is synthesized, and its structure is determined by single-crystal x-ray diffraction: a new structure type, sp. gr. PSymbol, a = 2.52015(3) nm, c = 0.330070(5) nm; RF = 0.054, Rw = 0.058 for 1894 independent reflections with Fhkl > 4.0σ(Fhkl). V3.2Mo8.8P7 is shown to contain mixed-occupancy (V, Mo) sites. The (V,Mo)84P49 and (Ti,Mo)36P21 structure types belong to a homologous series containing Cr12P7 as the n = 1 member.