The structure described by CaB2Si2O8 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. B(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form BO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra and corners with three equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent B(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 2-coordinate geometry to one Ca(1), one B(1), and one Si(1) atom. In the second O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one B(1), and one Si(1) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1) and two equivalent B(1) atoms. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one B(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_CaSi2(BO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.808
_cell_length_b   8.152
_cell_length_c   8.862
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   564.057
_cell_formula_units_Z   4
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  0.250  0.112  0.576  1.0
  Ca  Ca1  1  0.750  0.888  0.424  1.0
  Ca  Ca2  1  0.250  0.612  0.924  1.0
  Ca  Ca3  1  0.750  0.388  0.076  1.0
  Si  Si4  1  0.055  0.555  0.308  1.0
  Si  Si5  1  0.555  0.445  0.692  1.0
  Si  Si6  1  0.445  0.055  0.192  1.0
  Si  Si7  1  0.945  0.945  0.808  1.0
  Si  Si8  1  0.945  0.445  0.692  1.0
  Si  Si9  1  0.445  0.555  0.308  1.0
  Si  Si10  1  0.555  0.945  0.808  1.0
  Si  Si11  1  0.055  0.055  0.192  1.0
  B  B12  1  0.579  0.260  0.418  1.0
  B  B13  1  0.579  0.760  0.082  1.0
  B  B14  1  0.079  0.240  0.918  1.0
  B  B15  1  0.921  0.260  0.418  1.0
  B  B16  1  0.421  0.740  0.582  1.0
  B  B17  1  0.079  0.740  0.582  1.0
  B  B18  1  0.921  0.760  0.082  1.0
  B  B19  1  0.421  0.240  0.918  1.0
  O  O20  1  0.250  0.314  0.927  1.0
  O  O21  1  0.750  0.186  0.427  1.0
  O  O22  1  0.250  0.814  0.573  1.0
  O  O23  1  0.750  0.686  0.073  1.0
  O  O24  1  0.250  0.989  0.165  1.0
  O  O25  1  0.750  0.011  0.835  1.0
  O  O26  1  0.250  0.489  0.335  1.0
  O  O27  1  0.750  0.511  0.665  1.0
  O  O28  1  0.922  0.900  0.187  1.0
  O  O29  1  0.422  0.100  0.813  1.0
  O  O30  1  0.578  0.400  0.313  1.0
  O  O31  1  0.078  0.600  0.687  1.0
  O  O32  1  0.003  0.193  0.067  1.0
  O  O33  1  0.503  0.807  0.933  1.0
  O  O34  1  0.497  0.693  0.433  1.0
  O  O35  1  0.997  0.307  0.567  1.0
  O  O36  1  0.997  0.807  0.933  1.0
  O  O37  1  0.497  0.193  0.067  1.0
  O  O38  1  0.503  0.307  0.567  1.0
  O  O39  1  0.003  0.693  0.433  1.0
  O  O40  1  0.041  0.128  0.364  1.0
  O  O41  1  0.541  0.872  0.636  1.0
  O  O42  1  0.459  0.628  0.136  1.0
  O  O43  1  0.959  0.372  0.864  1.0
  O  O44  1  0.959  0.872  0.636  1.0
  O  O45  1  0.459  0.128  0.364  1.0
  O  O46  1  0.541  0.372  0.864  1.0
  O  O47  1  0.041  0.628  0.136  1.0
  O  O48  1  0.922  0.400  0.313  1.0
  O  O49  1  0.422  0.600  0.687  1.0
  O  O50  1  0.578  0.900  0.187  1.0
  O  O51  1  0.078  0.100  0.813  1.0
[/CIF]
.
The structure described by CaB2Si2O8 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. B(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form BO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra and corners with three equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent B(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 2-coordinate geometry to one Ca(1), one B(1), and one Si(1) atom. In the second O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one B(1), and one Si(1) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1) and two equivalent B(1) atoms. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one B(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_CaSi2(BO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.808
_cell_length_b   8.152
_cell_length_c   8.862
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   564.057
_cell_formula_units_Z   4
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  0.250  0.112  0.576  1.0
  Ca  Ca1  1  0.750  0.888  0.424  1.0
  Ca  Ca2  1  0.250  0.612  0.924  1.0
  Ca  Ca3  1  0.750  0.388  0.076  1.0
  Si  Si4  1  0.055  0.555  0.308  1.0
  Si  Si5  1  0.555  0.445  0.692  1.0
  Si  Si6  1  0.445  0.055  0.192  1.0
  Si  Si7  1  0.945  0.945  0.808  1.0
  Si  Si8  1  0.945  0.445  0.692  1.0
  Si  Si9  1  0.445  0.555  0.308  1.0
  Si  Si10  1  0.555  0.945  0.808  1.0
  Si  Si11  1  0.055  0.055  0.192  1.0
  B  B12  1  0.579  0.260  0.418  1.0
  B  B13  1  0.579  0.760  0.082  1.0
  B  B14  1  0.079  0.240  0.918  1.0
  B  B15  1  0.921  0.260  0.418  1.0
  B  B16  1  0.421  0.740  0.582  1.0
  B  B17  1  0.079  0.740  0.582  1.0
  B  B18  1  0.921  0.760  0.082  1.0
  B  B19  1  0.421  0.240  0.918  1.0
  O  O20  1  0.250  0.314  0.927  1.0
  O  O21  1  0.750  0.186  0.427  1.0
  O  O22  1  0.250  0.814  0.573  1.0
  O  O23  1  0.750  0.686  0.073  1.0
  O  O24  1  0.250  0.989  0.165  1.0
  O  O25  1  0.750  0.011  0.835  1.0
  O  O26  1  0.250  0.489  0.335  1.0
  O  O27  1  0.750  0.511  0.665  1.0
  O  O28  1  0.922  0.900  0.187  1.0
  O  O29  1  0.422  0.100  0.813  1.0
  O  O30  1  0.578  0.400  0.313  1.0
  O  O31  1  0.078  0.600  0.687  1.0
  O  O32  1  0.003  0.193  0.067  1.0
  O  O33  1  0.503  0.807  0.933  1.0
  O  O34  1  0.497  0.693  0.433  1.0
  O  O35  1  0.997  0.307  0.567  1.0
  O  O36  1  0.997  0.807  0.933  1.0
  O  O37  1  0.497  0.193  0.067  1.0
  O  O38  1  0.503  0.307  0.567  1.0
  O  O39  1  0.003  0.693  0.433  1.0
  O  O40  1  0.041  0.128  0.364  1.0
  O  O41  1  0.541  0.872  0.636  1.0
  O  O42  1  0.459  0.628  0.136  1.0
  O  O43  1  0.959  0.372  0.864  1.0
  O  O44  1  0.959  0.872  0.636  1.0
  O  O45  1  0.459  0.128  0.364  1.0
  O  O46  1  0.541  0.372  0.864  1.0
  O  O47  1  0.041  0.628  0.136  1.0
  O  O48  1  0.922  0.400  0.313  1.0
  O  O49  1  0.422  0.600  0.687  1.0
  O  O50  1  0.578  0.900  0.187  1.0
  O  O51  1  0.078  0.100  0.813  1.0
[/CIF]
.