Ca3B4(H4O)3 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to two equivalent H(5), two equivalent H(6), two equivalent H(7), one O(1), and two equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 11-coordinate geometry to one H(2), one H(3), one H(4), one H(5), one H(6), one H(7), two equivalent H(1), one O(1), and two equivalent O(2) atoms. There are three inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(2) atoms. In the second B site, B(2) is bonded in a tetrahedral geometry to one H(2), one H(3), and two equivalent H(1) atoms. In the third B site, B(3) is bonded in a tetrahedral geometry to one H(4), one H(5), one H(6), and one H(7) atom. There are seven inequivalent H sites. In the first H site, H(2) is bonded in a single-bond geometry to two equivalent Ca(2) and one B(2) atom. In the second H site, H(3) is bonded in a single-bond geometry to two equivalent Ca(2) and one B(2) atom. In the third H site, H(4) is bonded in a distorted single-bond geometry to one Ca(2) and one B(3) atom. In the fourth H site, H(5) is bonded in a single-bond geometry to one Ca(1), one Ca(2), and one B(3) atom. In the fifth H site, H(6) is bonded in a single-bond geometry to one Ca(1), one Ca(2), and one B(3) atom. In the sixth H site, H(7) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), and one B(3) atom. In the seventh H site, H(1) is bonded in a single-bond geometry to two equivalent Ca(2) and one B(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ca(1), two equivalent Ca(2), and one B(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ca(1), two equivalent Ca(2), and one B(1) atom.
Ca3B4(H4O)3 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to two equivalent H(5), two equivalent H(6), two equivalent H(7), one O(1), and two equivalent O(2) atoms. Both Ca(1)-H(5) bond lengths are 2.60 Å. Both Ca(1)-H(6) bond lengths are 2.52 Å. Both Ca(1)-H(7) bond lengths are 2.53 Å. The Ca(1)-O(1) bond length is 2.31 Å. Both Ca(1)-O(2) bond lengths are 2.42 Å. In the second Ca site, Ca(2) is bonded in a 11-coordinate geometry to one H(2), one H(3), one H(4), one H(5), one H(6), one H(7), two equivalent H(1), one O(1), and two equivalent O(2) atoms. The Ca(2)-H(2) bond length is 2.55 Å. The Ca(2)-H(3) bond length is 2.66 Å. The Ca(2)-H(4) bond length is 2.41 Å. The Ca(2)-H(5) bond length is 2.55 Å. The Ca(2)-H(6) bond length is 2.52 Å. The Ca(2)-H(7) bond length is 2.69 Å. There is one shorter (2.52 Å) and one longer (2.59 Å) Ca(2)-H(1) bond length. The Ca(2)-O(1) bond length is 2.42 Å. There is one shorter (2.31 Å) and one longer (2.45 Å) Ca(2)-O(2) bond length. There are three inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(2) atoms. The B(1)-O(1) bond length is 1.39 Å. Both B(1)-O(2) bond lengths are 1.39 Å. In the second B site, B(2) is bonded in a tetrahedral geometry to one H(2), one H(3), and two equivalent H(1) atoms. The B(2)-H(2) bond length is 1.23 Å. The B(2)-H(3) bond length is 1.22 Å. Both B(2)-H(1) bond lengths are 1.22 Å. In the third B site, B(3) is bonded in a tetrahedral geometry to one H(4), one H(5), one H(6), and one H(7) atom. The B(3)-H(4) bond length is 1.22 Å. The B(3)-H(5) bond length is 1.23 Å. The B(3)-H(6) bond length is 1.22 Å. The B(3)-H(7) bond length is 1.23 Å. There are seven inequivalent H sites. In the first H site, H(2) is bonded in a single-bond geometry to two equivalent Ca(2) and one B(2) atom. In the second H site, H(3) is bonded in a single-bond geometry to two equivalent Ca(2) and one B(2) atom. In the third H site, H(4) is bonded in a distorted single-bond geometry to one Ca(2) and one B(3) atom. In the fourth H site, H(5) is bonded in a single-bond geometry to one Ca(1), one Ca(2), and one B(3) atom. In the fifth H site, H(6) is bonded in a single-bond geometry to one Ca(1), one Ca(2), and one B(3) atom. In the sixth H site, H(7) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), and one B(3) atom. In the seventh H site, H(1) is bonded in a single-bond geometry to two equivalent Ca(2) and one B(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ca(1), two equivalent Ca(2), and one B(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ca(1), two equivalent Ca(2), and one B(1) atom.