The compound described by CaAlB3O7 crystallizes in the orthorhombic Cmme space group. Ca(1) is bonded in a q6 geometry to two equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with two equivalent B(1)O4 tetrahedra, corners with four equivalent B(2)O4 tetrahedra, and edges with two equivalent B(1)O4 tetrahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form BO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one B(1)O4 tetrahedra, corners with two equivalent B(2)O4 tetrahedra, and  an edgeedge with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second B site, B(2) is bonded to four equivalent O(2) atoms to form BO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with four equivalent B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Ca(1), one Al(1), and one B(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Al(1), one B(1), and one B(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent B(1) atoms. is represented by the CIF file [CIF]
data_CaAlB3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.142
_cell_length_b   7.142
_cell_length_c   4.412
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   111.531
_symmetry_Int_Tables_number   1
_cell_volume   209.360
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.000  0.500  0.000  1.0
  Ca  Ca1  1  0.500  0.000  0.000  1.0
  Al  Al2  1  0.500  0.500  0.000  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
  B  B4  1  0.863  0.137  0.459  1.0
  B  B5  1  0.363  0.637  0.541  1.0
  B  B6  1  0.250  0.250  0.500  1.0
  B  B7  1  0.637  0.363  0.459  1.0
  B  B8  1  0.137  0.863  0.541  1.0
  B  B9  1  0.750  0.750  0.500  1.0
  O  O10  1  0.131  0.869  0.224  1.0
  O  O11  1  0.631  0.369  0.776  1.0
  O  O12  1  0.281  0.427  0.699  1.0
  O  O13  1  0.573  0.719  0.699  1.0
  O  O14  1  0.219  0.073  0.699  1.0
  O  O15  1  0.719  0.573  0.301  1.0
  O  O16  1  0.927  0.781  0.699  1.0
  O  O17  1  0.869  0.131  0.776  1.0
  O  O18  1  0.427  0.281  0.301  1.0
  O  O19  1  0.750  0.250  0.330  1.0
  O  O20  1  0.250  0.750  0.670  1.0
  O  O21  1  0.781  0.927  0.301  1.0
  O  O22  1  0.073  0.219  0.301  1.0
  O  O23  1  0.369  0.631  0.224  1.0
[/CIF]
.
The compound described by CaAlB3O7 crystallizes in the orthorhombic Cmme space group. Ca(1) is bonded in a q6 geometry to two equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with two equivalent B(1)O4 tetrahedra, corners with four equivalent B(2)O4 tetrahedra, and edges with two equivalent B(1)O4 tetrahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form BO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one B(1)O4 tetrahedra, corners with two equivalent B(2)O4 tetrahedra, and  an edgeedge with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second B site, B(2) is bonded to four equivalent O(2) atoms to form BO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with four equivalent B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Ca(1), one Al(1), and one B(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Al(1), one B(1), and one B(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent B(1) atoms. is represented by the CIF file [CIF]
data_CaAlB3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.142
_cell_length_b   7.142
_cell_length_c   4.412
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   111.531
_symmetry_Int_Tables_number   1
_cell_volume   209.360
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.000  0.500  0.000  1.0
  Ca  Ca1  1  0.500  0.000  0.000  1.0
  Al  Al2  1  0.500  0.500  0.000  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
  B  B4  1  0.863  0.137  0.459  1.0
  B  B5  1  0.363  0.637  0.541  1.0
  B  B6  1  0.250  0.250  0.500  1.0
  B  B7  1  0.637  0.363  0.459  1.0
  B  B8  1  0.137  0.863  0.541  1.0
  B  B9  1  0.750  0.750  0.500  1.0
  O  O10  1  0.131  0.869  0.224  1.0
  O  O11  1  0.631  0.369  0.776  1.0
  O  O12  1  0.281  0.427  0.699  1.0
  O  O13  1  0.573  0.719  0.699  1.0
  O  O14  1  0.219  0.073  0.699  1.0
  O  O15  1  0.719  0.573  0.301  1.0
  O  O16  1  0.927  0.781  0.699  1.0
  O  O17  1  0.869  0.131  0.776  1.0
  O  O18  1  0.427  0.281  0.301  1.0
  O  O19  1  0.750  0.250  0.330  1.0
  O  O20  1  0.250  0.750  0.670  1.0
  O  O21  1  0.781  0.927  0.301  1.0
  O  O22  1  0.073  0.219  0.301  1.0
  O  O23  1  0.369  0.631  0.224  1.0
[/CIF]
.