FeCuBi2(AsO6)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(12), two equivalent O(3), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Cu(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. In the second Cu site, Cu(2) is bonded to two equivalent O(1), two equivalent O(12), and two equivalent O(3) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(7), one O(8), and two equivalent O(9) atoms. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(6), one O(9), and two equivalent O(7) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(4), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Cu(1)O6 octahedra, and  a cornercorner with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-64°. In the second As site, As(2) is bonded to one O(10), one O(11), one O(3), and one O(6) atom to form AsO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Cu(1)O6 octahedra, and  a cornercorner with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-63°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cu(2), one Bi(1), and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(2), one Cu(1), and one As(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Fe(1), one Cu(2), and one As(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Bi(1) and one As(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(2) and one Cu(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Bi(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Bi(1) and two equivalent Bi(2) atoms. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Fe(1), one Bi(1), and one As(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Bi(2) and two equivalent Bi(1) atoms. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Bi(2) and one As(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Fe(2), one Bi(2), and one As(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Fe(1) and one Cu(2) atom.
FeCuBi2(AsO6)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(12), two equivalent O(3), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Cu(2)O6 octahedra. Both Fe(1)-O(12) bond lengths are 1.89 Å. Both Fe(1)-O(3) bond lengths are 1.99 Å. Both Fe(1)-O(8) bond lengths are 2.01 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. Both Fe(2)-O(11) bond lengths are 2.01 Å. Both Fe(2)-O(2) bond lengths are 1.99 Å. Both Fe(2)-O(5) bond lengths are 1.89 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. Both Cu(1)-O(2) bond lengths are 2.42 Å. Both Cu(1)-O(5) bond lengths are 1.85 Å. Both Cu(1)-O(6) bond lengths are 1.91 Å. In the second Cu site, Cu(2) is bonded to two equivalent O(1), two equivalent O(12), and two equivalent O(3) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. Both Cu(2)-O(1) bond lengths are 1.91 Å. Both Cu(2)-O(12) bond lengths are 1.85 Å. Both Cu(2)-O(3) bond lengths are 2.41 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(7), one O(8), and two equivalent O(9) atoms. The Bi(1)-O(1) bond length is 2.57 Å. The Bi(1)-O(4) bond length is 2.25 Å. The Bi(1)-O(7) bond length is 2.46 Å. The Bi(1)-O(8) bond length is 2.62 Å. There is one shorter (2.18 Å) and one longer (2.28 Å) Bi(1)-O(9) bond length. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(6), one O(9), and two equivalent O(7) atoms. The Bi(2)-O(10) bond length is 2.26 Å. The Bi(2)-O(11) bond length is 2.61 Å. The Bi(2)-O(6) bond length is 2.57 Å. The Bi(2)-O(9) bond length is 2.48 Å. There is one shorter (2.18 Å) and one longer (2.28 Å) Bi(2)-O(7) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(4), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Cu(1)O6 octahedra, and  a cornercorner with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-64°. The As(1)-O(1) bond length is 1.75 Å. The As(1)-O(2) bond length is 1.70 Å. The As(1)-O(4) bond length is 1.71 Å. The As(1)-O(8) bond length is 1.73 Å. In the second As site, As(2) is bonded to one O(10), one O(11), one O(3), and one O(6) atom to form AsO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Cu(1)O6 octahedra, and  a cornercorner with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-63°. The As(2)-O(10) bond length is 1.71 Å. The As(2)-O(11) bond length is 1.73 Å. The As(2)-O(3) bond length is 1.70 Å. The As(2)-O(6) bond length is 1.75 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cu(2), one Bi(1), and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(2), one Cu(1), and one As(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Fe(1), one Cu(2), and one As(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Bi(1) and one As(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(2) and one Cu(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Bi(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Bi(1) and two equivalent Bi(2) atoms. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Fe(1), one Bi(1), and one As(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Bi(2) and two equivalent Bi(1) atoms. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Bi(2) and one As(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Fe(2), one Bi(2), and one As(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Fe(1) and one Cu(2) atom.