Ca2B8H2O15 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 10-coordinate geometry to one O(1), one O(10), one O(13), one O(14), one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(11), one O(15), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. There are eight inequivalent B sites. In the first B site, B(1) is bonded to one O(14), one O(15), one O(2), and one O(8) atom to form corner-sharing BO4 tetrahedra. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(10), and one O(9) atom. In the third B site, B(3) is bonded in a trigonal planar geometry to one O(10), one O(4), and one O(7) atom. In the fourth B site, B(4) is bonded in a trigonal planar geometry to one O(14), one O(5), and one O(6) atom. In the fifth B site, B(5) is bonded in a trigonal planar geometry to one O(12), one O(13), and one O(15) atom. In the sixth B site, B(6) is bonded in a tetrahedral geometry to one O(1), one O(12), one O(6), and one O(7) atom. In the seventh B site, B(7) is bonded to one O(4), one O(5), one O(8), and one O(9) atom to form corner-sharing BO4 tetrahedra. In the eighth B site, B(8) is bonded to one O(11), one O(13), one O(2), and one O(3) atom to form corner-sharing BO4 tetrahedra. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(11) atom. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(2), and one B(6) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), one B(1), and one B(8) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to two equivalent Ca(1), one B(8), and one H(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), one B(3), and one B(7) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), one B(4), and one B(7) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one B(4), and one B(6) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ca(2), one B(3), and one B(6) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Ca(2), one B(1), and one B(7) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Ca(2), one B(2), and one B(7) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(2), and one B(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(2), one B(8), and one H(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one B(5) and one B(6) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(5), and one B(8) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(1), and one B(4) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 120 degrees geometry to one Ca(2), one B(1), and one B(5) atom.
Ca2B8H2O15 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 10-coordinate geometry to one O(1), one O(10), one O(13), one O(14), one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms. The Ca(1)-O(1) bond length is 2.72 Å. The Ca(1)-O(10) bond length is 2.56 Å. The Ca(1)-O(13) bond length is 2.52 Å. The Ca(1)-O(14) bond length is 2.57 Å. The Ca(1)-O(2) bond length is 2.50 Å. The Ca(1)-O(4) bond length is 3.08 Å. The Ca(1)-O(5) bond length is 2.72 Å. The Ca(1)-O(6) bond length is 2.60 Å. There is one shorter (2.50 Å) and one longer (2.52 Å) Ca(1)-O(3) bond length. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(11), one O(15), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. The Ca(2)-O(11) bond length is 2.38 Å. The Ca(2)-O(15) bond length is 2.59 Å. The Ca(2)-O(2) bond length is 2.74 Å. The Ca(2)-O(4) bond length is 2.69 Å. The Ca(2)-O(5) bond length is 2.44 Å. The Ca(2)-O(7) bond length is 2.51 Å. The Ca(2)-O(8) bond length is 2.40 Å. The Ca(2)-O(9) bond length is 2.48 Å. There are eight inequivalent B sites. In the first B site, B(1) is bonded to one O(14), one O(15), one O(2), and one O(8) atom to form corner-sharing BO4 tetrahedra. The B(1)-O(14) bond length is 1.52 Å. The B(1)-O(15) bond length is 1.50 Å. The B(1)-O(2) bond length is 1.46 Å. The B(1)-O(8) bond length is 1.46 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(10), and one O(9) atom. The B(2)-O(1) bond length is 1.35 Å. The B(2)-O(10) bond length is 1.41 Å. The B(2)-O(9) bond length is 1.37 Å. In the third B site, B(3) is bonded in a trigonal planar geometry to one O(10), one O(4), and one O(7) atom. The B(3)-O(10) bond length is 1.39 Å. The B(3)-O(4) bond length is 1.38 Å. The B(3)-O(7) bond length is 1.36 Å. In the fourth B site, B(4) is bonded in a trigonal planar geometry to one O(14), one O(5), and one O(6) atom. The B(4)-O(14) bond length is 1.37 Å. The B(4)-O(5) bond length is 1.41 Å. The B(4)-O(6) bond length is 1.37 Å. In the fifth B site, B(5) is bonded in a trigonal planar geometry to one O(12), one O(13), and one O(15) atom. The B(5)-O(12) bond length is 1.38 Å. The B(5)-O(13) bond length is 1.38 Å. The B(5)-O(15) bond length is 1.39 Å. In the sixth B site, B(6) is bonded in a tetrahedral geometry to one O(1), one O(12), one O(6), and one O(7) atom. The B(6)-O(1) bond length is 1.48 Å. The B(6)-O(12) bond length is 1.47 Å. The B(6)-O(6) bond length is 1.46 Å. The B(6)-O(7) bond length is 1.49 Å. In the seventh B site, B(7) is bonded to one O(4), one O(5), one O(8), and one O(9) atom to form corner-sharing BO4 tetrahedra. The B(7)-O(4) bond length is 1.50 Å. The B(7)-O(5) bond length is 1.50 Å. The B(7)-O(8) bond length is 1.44 Å. The B(7)-O(9) bond length is 1.51 Å. In the eighth B site, B(8) is bonded to one O(11), one O(13), one O(2), and one O(3) atom to form corner-sharing BO4 tetrahedra. The B(8)-O(11) bond length is 1.47 Å. The B(8)-O(13) bond length is 1.49 Å. The B(8)-O(2) bond length is 1.46 Å. The B(8)-O(3) bond length is 1.53 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. The H(1)-O(3) bond length is 0.98 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(11) atom. The H(2)-O(11) bond length is 0.97 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(2), and one B(6) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), one B(1), and one B(8) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to two equivalent Ca(1), one B(8), and one H(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), one B(3), and one B(7) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), one B(4), and one B(7) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one B(4), and one B(6) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ca(2), one B(3), and one B(6) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Ca(2), one B(1), and one B(7) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Ca(2), one B(2), and one B(7) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(2), and one B(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(2), one B(8), and one H(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one B(5) and one B(6) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(5), and one B(8) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one B(1), and one B(4) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 120 degrees geometry to one Ca(2), one B(1), and one B(5) atom.