Ca5(AsO4)3OH crystallizes in the hexagonal P6_3 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms. As(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. H(1) is bonded in a single-bond geometry to one O(5) atom. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(3) and one As(1) atom. In the second O site, O(5) is bonded in a single-bond geometry to three equivalent Ca(3) and one H(1) atom. In the third O site, O(1) is bonded to one Ca(1), one Ca(2), one Ca(3), and one As(1) atom to form distorted edge-sharing OCa3As tetrahedra. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one As(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(3), and one As(1) atom.
Ca5(AsO4)3OH crystallizes in the hexagonal P6_3 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Ca(1)-O(1) bond lengths are 2.49 Å. All Ca(1)-O(2) bond lengths are 2.40 Å. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. All Ca(2)-O(1) bond lengths are 2.50 Å. All Ca(2)-O(2) bond lengths are 2.41 Å. All Ca(2)-O(3) bond lengths are 2.93 Å. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms. The Ca(3)-O(1) bond length is 2.42 Å. The Ca(3)-O(5) bond length is 2.45 Å. There is one shorter (2.35 Å) and one longer (2.50 Å) Ca(3)-O(3) bond length. There is one shorter (2.36 Å) and one longer (2.47 Å) Ca(3)-O(4) bond length. As(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The As(1)-O(1) bond length is 1.73 Å. The As(1)-O(2) bond length is 1.71 Å. The As(1)-O(3) bond length is 1.72 Å. The As(1)-O(4) bond length is 1.72 Å. H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(3) and one As(1) atom. In the second O site, O(5) is bonded in a single-bond geometry to three equivalent Ca(3) and one H(1) atom. In the third O site, O(1) is bonded to one Ca(1), one Ca(2), one Ca(3), and one As(1) atom to form distorted edge-sharing OCa3As tetrahedra. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one As(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(3), and one As(1) atom.