Cr4O15 is Indium-like structured and crystallizes in the monoclinic Pc space group. The structure is zero-dimensional and consists of two Cr4O15 clusters. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form corner-sharing CrO4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(10), one O(3), one O(5), and one O(9) atom to form corner-sharing CrO4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(12), one O(2), one O(4), and one O(7) atom to form corner-sharing CrO4 tetrahedra. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(13), one O(4), and one O(8) atom to form corner-sharing CrO4 tetrahedra. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Cr(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Cr(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cr(3) and one Cr(4) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Cr(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Cr(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Cr(4) and one O(14) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one O(15) atom. In the tenth O site, O(10) is bonded in a single-bond geometry to one Cr(2) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Cr(4) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Cr(3) atom. In the thirteenth O site, O(13) is bonded in a single-bond geometry to one Cr(4) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one O(8) atom. In the fifteenth O site, O(15) is bonded in a single-bond geometry to one O(9) atom.
Cr4O15 is Indium-like structured and crystallizes in the monoclinic Pc space group. The structure is zero-dimensional and consists of two Cr4O15 clusters. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form corner-sharing CrO4 tetrahedra. The Cr(1)-O(1) bond length is 1.59 Å. The Cr(1)-O(3) bond length is 1.77 Å. The Cr(1)-O(6) bond length is 1.60 Å. The Cr(1)-O(7) bond length is 1.79 Å. In the second Cr site, Cr(2) is bonded to one O(10), one O(3), one O(5), and one O(9) atom to form corner-sharing CrO4 tetrahedra. The Cr(2)-O(10) bond length is 1.60 Å. The Cr(2)-O(3) bond length is 1.78 Å. The Cr(2)-O(5) bond length is 1.60 Å. The Cr(2)-O(9) bond length is 1.92 Å. In the third Cr site, Cr(3) is bonded to one O(12), one O(2), one O(4), and one O(7) atom to form corner-sharing CrO4 tetrahedra. The Cr(3)-O(12) bond length is 1.59 Å. The Cr(3)-O(2) bond length is 1.60 Å. The Cr(3)-O(4) bond length is 1.78 Å. The Cr(3)-O(7) bond length is 1.77 Å. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(13), one O(4), and one O(8) atom to form corner-sharing CrO4 tetrahedra. The Cr(4)-O(11) bond length is 1.60 Å. The Cr(4)-O(13) bond length is 1.60 Å. The Cr(4)-O(4) bond length is 1.79 Å. The Cr(4)-O(8) bond length is 1.91 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Cr(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Cr(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cr(3) and one Cr(4) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Cr(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Cr(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Cr(4) and one O(14) atom. The O(8)-O(14) bond length is 1.27 Å. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one O(15) atom. The O(9)-O(15) bond length is 1.27 Å. In the tenth O site, O(10) is bonded in a single-bond geometry to one Cr(2) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Cr(4) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Cr(3) atom. In the thirteenth O site, O(13) is bonded in a single-bond geometry to one Cr(4) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one O(8) atom. In the fifteenth O site, O(15) is bonded in a single-bond geometry to one O(9) atom.