FeAgBr4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one Br(1), one Br(2), one Br(3), and one Br(4) atom to form FeBr4 tetrahedra that share corners with two equivalent Ag(1)Br6 octahedra and edges with two equivalent Ag(1)Br6 octahedra. The corner-sharing octahedral tilt angles range from 60-61°. Ag(1) is bonded to one Br(1), one Br(3), two equivalent Br(2), and two equivalent Br(4) atoms to form AgBr6 octahedra that share corners with two equivalent Ag(1)Br6 octahedra, corners with two equivalent Fe(1)Br4 tetrahedra,  an edgeedge with one Ag(1)Br6 octahedra, and edges with two equivalent Fe(1)Br4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one Ag(1) atom. In the second Br site, Br(2) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Ag(1) atoms. In the third Br site, Br(3) is bonded in an L-shaped geometry to one Fe(1) and one Ag(1) atom. In the fourth Br site, Br(4) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Ag(1) atoms.
FeAgBr4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one Br(1), one Br(2), one Br(3), and one Br(4) atom to form FeBr4 tetrahedra that share corners with two equivalent Ag(1)Br6 octahedra and edges with two equivalent Ag(1)Br6 octahedra. The corner-sharing octahedral tilt angles range from 60-61°. The Fe(1)-Br(1) bond length is 2.34 Å. The Fe(1)-Br(2) bond length is 2.38 Å. The Fe(1)-Br(3) bond length is 2.34 Å. The Fe(1)-Br(4) bond length is 2.38 Å. Ag(1) is bonded to one Br(1), one Br(3), two equivalent Br(2), and two equivalent Br(4) atoms to form AgBr6 octahedra that share corners with two equivalent Ag(1)Br6 octahedra, corners with two equivalent Fe(1)Br4 tetrahedra,  an edgeedge with one Ag(1)Br6 octahedra, and edges with two equivalent Fe(1)Br4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. The Ag(1)-Br(1) bond length is 2.78 Å. The Ag(1)-Br(3) bond length is 2.78 Å. There is one shorter (2.87 Å) and one longer (2.96 Å) Ag(1)-Br(2) bond length. There is one shorter (2.93 Å) and one longer (2.97 Å) Ag(1)-Br(4) bond length. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one Ag(1) atom. In the second Br site, Br(2) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Ag(1) atoms. In the third Br site, Br(3) is bonded in an L-shaped geometry to one Fe(1) and one Ag(1) atom. In the fourth Br site, Br(4) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Ag(1) atoms.