This paper reports a new partially oxidized triphylite-type phosphate (lithium iron phosphate), which has been synthesized hydrothermally at 973 K and 0.1 GPa. The structure is similar to that of natural triphylite, LiFe(PO(4)), and is characterized by two chains of edge-sharing octahedra parallel to the b axis. The weakly distorted M1 octahedra contain Li atoms, whereas the more strongly distorted M2 octahedra contain Fe(II) and Fe(III) atoms. Refined site occupancies and bond-valence analysis show the presence of Fe(III) and vacancies on the M2 site, mainly explained by the substitution mechanism 3 Fe(II) = 2 Fe(III) + vacancies.