Cs7Ni4F15 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one F(2), one F(3), one F(4), one F(7), two equivalent F(1), and two equivalent F(6) atoms. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to one F(1), one F(2), one F(3), one F(6), one F(7), one F(8), two equivalent F(4), and two equivalent F(5) atoms. In the third Cs site, Cs(3) is bonded in a 10-coordinate geometry to one F(1), one F(2), one F(4), one F(5), one F(7), one F(8), two equivalent F(3), and two equivalent F(6) atoms. In the fourth Cs site, Cs(4) is bonded in a 10-coordinate geometry to two equivalent F(1), two equivalent F(2), two equivalent F(4), two equivalent F(5), and two equivalent F(7) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one F(1), one F(2), one F(3), one F(5), one F(6), and one F(7) atom to form a mixture of face and corner-sharing NiF6 octahedra. The corner-sharing octahedral tilt angles are 6°. In the second Ni site, Ni(2) is bonded to one F(2), one F(3), one F(4), one F(5), one F(7), and one F(8) atom to form a mixture of face and corner-sharing NiF6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. There are eight inequivalent F sites. In the first F site, F(7) is bonded in a distorted linear geometry to one Cs(1), one Cs(2), one Cs(3), one Cs(4), one Ni(1), and one Ni(2) atom. In the second F site, F(8) is bonded in a linear geometry to two equivalent Cs(2), two equivalent Cs(3), and two equivalent Ni(2) atoms. In the third F site, F(1) is bonded in a distorted single-bond geometry to one Cs(2), one Cs(3), one Cs(4), two equivalent Cs(1), and one Ni(1) atom. In the fourth F site, F(2) is bonded to one Cs(1), one Cs(2), one Cs(3), one Cs(4), one Ni(1), and one Ni(2) atom to form a mixture of distorted face and corner-sharing FCs4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-71°. In the fifth F site, F(3) is bonded in a 2-coordinate geometry to one Cs(1), one Cs(2), two equivalent Cs(3), one Ni(1), and one Ni(2) atom. In the sixth F site, F(4) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(3), one Cs(4), two equivalent Cs(2), and one Ni(2) atom. In the seventh F site, F(5) is bonded to one Cs(3), one Cs(4), two equivalent Cs(2), one Ni(1), and one Ni(2) atom to form a mixture of distorted face and corner-sharing FCs4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-71°. In the eighth F site, F(6) is bonded in a distorted single-bond geometry to one Cs(2), two equivalent Cs(1), two equivalent Cs(3), and one Ni(1) atom.
Cs7Ni4F15 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one F(2), one F(3), one F(4), one F(7), two equivalent F(1), and two equivalent F(6) atoms. The Cs(1)-F(2) bond length is 2.98 Å. The Cs(1)-F(3) bond length is 3.01 Å. The Cs(1)-F(4) bond length is 2.92 Å. The Cs(1)-F(7) bond length is 3.12 Å. Both Cs(1)-F(1) bond lengths are 2.95 Å. Both Cs(1)-F(6) bond lengths are 2.96 Å. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to one F(1), one F(2), one F(3), one F(6), one F(7), one F(8), two equivalent F(4), and two equivalent F(5) atoms. The Cs(2)-F(1) bond length is 3.04 Å. The Cs(2)-F(2) bond length is 3.03 Å. The Cs(2)-F(3) bond length is 3.08 Å. The Cs(2)-F(6) bond length is 2.99 Å. The Cs(2)-F(7) bond length is 3.09 Å. The Cs(2)-F(8) bond length is 3.12 Å. There is one shorter (3.02 Å) and one longer (3.08 Å) Cs(2)-F(4) bond length. There is one shorter (3.03 Å) and one longer (3.08 Å) Cs(2)-F(5) bond length. In the third Cs site, Cs(3) is bonded in a 10-coordinate geometry to one F(1), one F(2), one F(4), one F(5), one F(7), one F(8), two equivalent F(3), and two equivalent F(6) atoms. The Cs(3)-F(1) bond length is 3.35 Å. The Cs(3)-F(2) bond length is 3.17 Å. The Cs(3)-F(4) bond length is 3.14 Å. The Cs(3)-F(5) bond length is 3.11 Å. The Cs(3)-F(7) bond length is 3.04 Å. The Cs(3)-F(8) bond length is 3.15 Å. There is one shorter (3.09 Å) and one longer (3.31 Å) Cs(3)-F(3) bond length. There is one shorter (3.09 Å) and one longer (3.24 Å) Cs(3)-F(6) bond length. In the fourth Cs site, Cs(4) is bonded in a 10-coordinate geometry to two equivalent F(1), two equivalent F(2), two equivalent F(4), two equivalent F(5), and two equivalent F(7) atoms. Both Cs(4)-F(1) bond lengths are 3.02 Å. Both Cs(4)-F(2) bond lengths are 3.13 Å. Both Cs(4)-F(4) bond lengths are 3.14 Å. Both Cs(4)-F(5) bond lengths are 3.18 Å. Both Cs(4)-F(7) bond lengths are 3.28 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one F(1), one F(2), one F(3), one F(5), one F(6), and one F(7) atom to form a mixture of face and corner-sharing NiF6 octahedra. The corner-sharing octahedral tilt angles are 6°. The Ni(1)-F(1) bond length is 1.96 Å. The Ni(1)-F(2) bond length is 2.06 Å. The Ni(1)-F(3) bond length is 2.09 Å. The Ni(1)-F(5) bond length is 2.06 Å. The Ni(1)-F(6) bond length is 1.97 Å. The Ni(1)-F(7) bond length is 2.04 Å. In the second Ni site, Ni(2) is bonded to one F(2), one F(3), one F(4), one F(5), one F(7), and one F(8) atom to form a mixture of face and corner-sharing NiF6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. The Ni(2)-F(2) bond length is 2.06 Å. The Ni(2)-F(3) bond length is 2.04 Å. The Ni(2)-F(4) bond length is 1.95 Å. The Ni(2)-F(5) bond length is 2.05 Å. The Ni(2)-F(7) bond length is 2.03 Å. The Ni(2)-F(8) bond length is 2.04 Å. There are eight inequivalent F sites. In the first F site, F(7) is bonded in a distorted linear geometry to one Cs(1), one Cs(2), one Cs(3), one Cs(4), one Ni(1), and one Ni(2) atom. In the second F site, F(8) is bonded in a linear geometry to two equivalent Cs(2), two equivalent Cs(3), and two equivalent Ni(2) atoms. In the third F site, F(1) is bonded in a distorted single-bond geometry to one Cs(2), one Cs(3), one Cs(4), two equivalent Cs(1), and one Ni(1) atom. In the fourth F site, F(2) is bonded to one Cs(1), one Cs(2), one Cs(3), one Cs(4), one Ni(1), and one Ni(2) atom to form a mixture of distorted face and corner-sharing FCs4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-71°. In the fifth F site, F(3) is bonded in a 2-coordinate geometry to one Cs(1), one Cs(2), two equivalent Cs(3), one Ni(1), and one Ni(2) atom. In the sixth F site, F(4) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(3), one Cs(4), two equivalent Cs(2), and one Ni(2) atom. In the seventh F site, F(5) is bonded to one Cs(3), one Cs(4), two equivalent Cs(2), one Ni(1), and one Ni(2) atom to form a mixture of distorted face and corner-sharing FCs4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-71°. In the eighth F site, F(6) is bonded in a distorted single-bond geometry to one Cs(2), two equivalent Cs(1), two equivalent Cs(3), and one Ni(1) atom.