CaFeBP2(HO5)2 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted CaO8 hexagonal bipyramids that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one B(1)O4 tetrahedra, and edges with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-48°. Fe(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four equivalent Ca(1)O8 hexagonal bipyramids, corners with two equivalent B(1)O4 tetrahedra, and corners with four equivalent P(1)O4 tetrahedra. B(1) is bonded to two equivalent O(4) and two equivalent O(5) atoms to form BO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one Ca(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 54°. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ca(1)O8 hexagonal bipyramids, corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one B(1)O4 tetrahedra, and  an edgeedge with one Ca(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 51°. 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(2) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one P(1) atom. In the second O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one P(1) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one B(1), and one P(1) atom. In the fourth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one B(1), and one H(1) atom. In the fifth O site, O(1) is bonded in a 2-coordinate geometry to one Ca(1) and one P(1) atom.
CaFeBP2(HO5)2 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted CaO8 hexagonal bipyramids that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one B(1)O4 tetrahedra, and edges with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-48°. Both Ca(1)-O(1) bond lengths are 2.41 Å. Both Ca(1)-O(2) bond lengths are 2.54 Å. Both Ca(1)-O(3) bond lengths are 2.62 Å. Both Ca(1)-O(4) bond lengths are 2.49 Å. Fe(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four equivalent Ca(1)O8 hexagonal bipyramids, corners with two equivalent B(1)O4 tetrahedra, and corners with four equivalent P(1)O4 tetrahedra. Both Fe(1)-O(2) bond lengths are 2.05 Å. Both Fe(1)-O(3) bond lengths are 1.98 Å. Both Fe(1)-O(5) bond lengths are 2.07 Å. B(1) is bonded to two equivalent O(4) and two equivalent O(5) atoms to form BO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one Ca(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 54°. Both B(1)-O(4) bond lengths are 1.49 Å. Both B(1)-O(5) bond lengths are 1.47 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ca(1)O8 hexagonal bipyramids, corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one B(1)O4 tetrahedra, and  an edgeedge with one Ca(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 51°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.59 Å. H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 1.00 Å. There are five inequivalent O sites. In the first O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one P(1) atom. In the second O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one P(1) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one B(1), and one P(1) atom. In the fourth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one B(1), and one H(1) atom. In the fifth O site, O(1) is bonded in a 2-coordinate geometry to one Ca(1) and one P(1) atom.