The crystal structure described by BaEr2Si3O10 crystallizes in the monoclinic P2_1/m space group. Ba(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Er(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(6) atoms to form distorted ErO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Si(2)O4 tetrahedra, and edges with two equivalent Er(1)O6 octahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with four equivalent Er(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share corners with four equivalent Er(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-60°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Er(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Er(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Er(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ba(1), one Er(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Er(1) and one Si(2) atom. is represented by the CIF file [CIF]
data_BaEr2Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.156
_cell_length_b   5.379
_cell_length_c   6.822
_cell_angle_alpha   73.344
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   427.412
_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
  Ba  Ba0  1  0.250  0.241  0.021  1.0
  Ba  Ba1  1  0.750  0.759  0.979  1.0
  Er  Er2  1  0.100  0.845  0.682  1.0
  Er  Er3  1  0.600  0.155  0.318  1.0
  Er  Er4  1  0.900  0.155  0.318  1.0
  Er  Er5  1  0.400  0.845  0.682  1.0
  Si  Si6  1  0.250  0.419  0.489  1.0
  Si  Si7  1  0.750  0.581  0.511  1.0
  Si  Si8  1  0.060  0.695  0.213  1.0
  Si  Si9  1  0.560  0.305  0.787  1.0
  Si  Si10  1  0.940  0.305  0.787  1.0
  Si  Si11  1  0.440  0.695  0.213  1.0
  O  O12  1  0.250  0.634  0.612  1.0
  O  O13  1  0.750  0.366  0.388  1.0
  O  O14  1  0.250  0.123  0.636  1.0
  O  O15  1  0.750  0.877  0.364  1.0
  O  O16  1  0.143  0.452  0.338  1.0
  O  O17  1  0.643  0.548  0.662  1.0
  O  O18  1  0.857  0.548  0.662  1.0
  O  O19  1  0.357  0.452  0.338  1.0
  O  O20  1  0.944  0.562  0.193  1.0
  O  O21  1  0.444  0.438  0.807  1.0
  O  O22  1  0.056  0.438  0.807  1.0
  O  O23  1  0.556  0.562  0.193  1.0
  O  O24  1  0.121  0.837  0.000  1.0
  O  O25  1  0.621  0.163  1.000  1.0
  O  O26  1  0.879  0.163  1.000  1.0
  O  O27  1  0.379  0.837  0.000  1.0
  O  O28  1  0.049  0.898  0.352  1.0
  O  O29  1  0.549  0.102  0.648  1.0
  O  O30  1  0.951  0.102  0.648  1.0
  O  O31  1  0.451  0.898  0.352  1.0
[/CIF]
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The crystal structure described by BaEr2Si3O10 crystallizes in the monoclinic P2_1/m space group. Ba(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Er(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(6) atoms to form distorted ErO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Si(2)O4 tetrahedra, and edges with two equivalent Er(1)O6 octahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with four equivalent Er(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share corners with four equivalent Er(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-60°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Er(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Er(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Er(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ba(1), one Er(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Er(1) and one Si(2) atom. is represented by the CIF file [CIF]
data_BaEr2Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.156
_cell_length_b   5.379
_cell_length_c   6.822
_cell_angle_alpha   73.344
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   427.412
_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
  Ba  Ba0  1  0.250  0.241  0.021  1.0
  Ba  Ba1  1  0.750  0.759  0.979  1.0
  Er  Er2  1  0.100  0.845  0.682  1.0
  Er  Er3  1  0.600  0.155  0.318  1.0
  Er  Er4  1  0.900  0.155  0.318  1.0
  Er  Er5  1  0.400  0.845  0.682  1.0
  Si  Si6  1  0.250  0.419  0.489  1.0
  Si  Si7  1  0.750  0.581  0.511  1.0
  Si  Si8  1  0.060  0.695  0.213  1.0
  Si  Si9  1  0.560  0.305  0.787  1.0
  Si  Si10  1  0.940  0.305  0.787  1.0
  Si  Si11  1  0.440  0.695  0.213  1.0
  O  O12  1  0.250  0.634  0.612  1.0
  O  O13  1  0.750  0.366  0.388  1.0
  O  O14  1  0.250  0.123  0.636  1.0
  O  O15  1  0.750  0.877  0.364  1.0
  O  O16  1  0.143  0.452  0.338  1.0
  O  O17  1  0.643  0.548  0.662  1.0
  O  O18  1  0.857  0.548  0.662  1.0
  O  O19  1  0.357  0.452  0.338  1.0
  O  O20  1  0.944  0.562  0.193  1.0
  O  O21  1  0.444  0.438  0.807  1.0
  O  O22  1  0.056  0.438  0.807  1.0
  O  O23  1  0.556  0.562  0.193  1.0
  O  O24  1  0.121  0.837  0.000  1.0
  O  O25  1  0.621  0.163  1.000  1.0
  O  O26  1  0.879  0.163  1.000  1.0
  O  O27  1  0.379  0.837  0.000  1.0
  O  O28  1  0.049  0.898  0.352  1.0
  O  O29  1  0.549  0.102  0.648  1.0
  O  O30  1  0.951  0.102  0.648  1.0
  O  O31  1  0.451  0.898  0.352  1.0
[/CIF]
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