BaAlF5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 11-coordinate geometry to one F(1), one F(10), one F(3), one F(4), one F(6), one F(7), one F(9), two equivalent F(2), and two equivalent F(8) atoms. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one F(1), one F(2), one F(4), one F(6), one F(9), two equivalent F(10), two equivalent F(3), and two equivalent F(5) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one F(10), one F(3), one F(5), one F(6), one F(7), and one F(9) atom to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles range from 36-39°. In the second Al site, Al(2) is bonded to one F(1), one F(2), one F(4), one F(6), one F(7), and one F(8) atom to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles range from 36-39°. There are ten inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(2) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Al(2) atom. In the third F site, F(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(2) atom. In the fifth F site, F(5) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one Al(1) atom. In the sixth F site, F(6) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ba(2), one Al(1), and one Al(2) atom. In the seventh F site, F(7) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Al(1), and one Al(2) atom. In the eighth F site, F(8) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Al(2) atom. In the ninth F site, F(9) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(1) atom. In the tenth F site, F(10) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom.
BaAlF5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 11-coordinate geometry to one F(1), one F(10), one F(3), one F(4), one F(6), one F(7), one F(9), two equivalent F(2), and two equivalent F(8) atoms. The Ba(1)-F(1) bond length is 2.69 Å. The Ba(1)-F(10) bond length is 2.78 Å. The Ba(1)-F(3) bond length is 2.93 Å. The Ba(1)-F(4) bond length is 3.00 Å. The Ba(1)-F(6) bond length is 3.07 Å. The Ba(1)-F(7) bond length is 2.86 Å. The Ba(1)-F(9) bond length is 2.64 Å. There is one shorter (2.75 Å) and one longer (3.21 Å) Ba(1)-F(2) bond length. There is one shorter (2.76 Å) and one longer (2.78 Å) Ba(1)-F(8) bond length. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one F(1), one F(2), one F(4), one F(6), one F(9), two equivalent F(10), two equivalent F(3), and two equivalent F(5) atoms. The Ba(2)-F(1) bond length is 2.76 Å. The Ba(2)-F(2) bond length is 2.95 Å. The Ba(2)-F(4) bond length is 2.65 Å. The Ba(2)-F(6) bond length is 3.04 Å. The Ba(2)-F(9) bond length is 2.96 Å. There is one shorter (2.77 Å) and one longer (3.04 Å) Ba(2)-F(10) bond length. There is one shorter (2.82 Å) and one longer (3.05 Å) Ba(2)-F(3) bond length. There is one shorter (2.76 Å) and one longer (2.78 Å) Ba(2)-F(5) bond length. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one F(10), one F(3), one F(5), one F(6), one F(7), and one F(9) atom to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles range from 36-39°. The Al(1)-F(10) bond length is 1.79 Å. The Al(1)-F(3) bond length is 1.79 Å. The Al(1)-F(5) bond length is 1.77 Å. The Al(1)-F(6) bond length is 1.90 Å. The Al(1)-F(7) bond length is 1.86 Å. The Al(1)-F(9) bond length is 1.75 Å. In the second Al site, Al(2) is bonded to one F(1), one F(2), one F(4), one F(6), one F(7), and one F(8) atom to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles range from 36-39°. The Al(2)-F(1) bond length is 1.78 Å. The Al(2)-F(2) bond length is 1.78 Å. The Al(2)-F(4) bond length is 1.76 Å. The Al(2)-F(6) bond length is 1.86 Å. The Al(2)-F(7) bond length is 1.87 Å. The Al(2)-F(8) bond length is 1.79 Å. There are ten inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(2) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Al(2) atom. In the third F site, F(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(2) atom. In the fifth F site, F(5) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one Al(1) atom. In the sixth F site, F(6) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ba(2), one Al(1), and one Al(2) atom. In the seventh F site, F(7) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Al(1), and one Al(2) atom. In the eighth F site, F(8) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Al(2) atom. In the ninth F site, F(9) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Al(1) atom. In the tenth F site, F(10) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one Al(1) atom.