Abstract: Fe₂BP₃O₁₂ was synthesized by high temperature solid state reactions. Its crystal
structure was refined by powder X-ray diffraction methods, belonging to trigonal system with space group P3, a=8.02703(6)A, c=7.40168(9)A,
V=413.02(1)A³, D_x=3.2758(1)(g/cm³), Z=2. The full profile refinement resulted to R(I)=6.35%, R(p)=15.36% and R(dbw)=10.12%
for 55 parameters using 188 reflections and 18001 profile data points. The structure contains [BP₃O₁₂]^4- poly-anion, built by trigonal
planar BO₃ sharing the three corner oxygen atom with three PO₄ tetrahedra. And Fe₂O₉ bi-octahedra fused by two face-sharing FeO₆ connect
with the poly-anions forming three dimensional ordered structure. Compared with its chromium isotypic compound, Cr₂BP₃O₁₂, which shows NLO
property, the title compound may be a potential NLO material.

Key words: borophosphate, solid state synthesis, crystal structure, powder diffraction