The structure described by Sm2TiO5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(1), and three equivalent O(4) atoms. In the second Sm site, Sm(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form SmO6 octahedra that share corners with two equivalent Sm(2)O6 octahedra, corners with four equivalent Ti(1)O6 trigonal bipyramids, and edges with two equivalent Sm(2)O6 octahedra. The corner-sharing octahedral tilt angles are 67°. Ti(1) is bonded to one O(3), one O(4), one O(5), and three equivalent O(2) atoms to form distorted TiO6 trigonal bipyramids that share corners with four equivalent Sm(2)O6 octahedra, corners with two equivalent Ti(1)O6 trigonal bipyramids, and edges with two equivalent Ti(1)O6 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 50-64°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(3)Sm3Ti tetrahedra, corners with four equivalent O(4)Sm3Ti tetrahedra, corners with four equivalent O(1)Sm4 tetrahedra,  an edgeedge with one O(4)Sm3Ti tetrahedra, and edges with two equivalent O(3)Sm3Ti tetrahedra. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to three equivalent Ti(1) atoms. In the third O site, O(3) is bonded to one Sm(1), two equivalent Sm(2), and one Ti(1) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with four equivalent O(4)Sm3Ti tetrahedra, and edges with two equivalent O(1)Sm4 tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Sm(1) and one Ti(1) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(4)Sm3Ti tetrahedra, corners with four equivalent O(3)Sm3Ti tetrahedra, corners with four equivalent O(1)Sm4 tetrahedra,  an edgeedge with one O(1)Sm4 tetrahedra, and edges with two equivalent O(4)Sm3Ti tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Sm(2) and one Ti(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2TiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.697
_cell_length_b   7.630
_cell_length_c   15.897
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   448.396
_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
  Sm  Sm0  1  0.250  0.122  0.079  1.0
  Sm  Sm1  1  0.250  0.141  0.739  1.0
  Sm  Sm2  1  0.750  0.359  0.239  1.0
  Sm  Sm3  1  0.750  0.378  0.579  1.0
  Sm  Sm4  1  0.250  0.622  0.421  1.0
  Sm  Sm5  1  0.250  0.641  0.761  1.0
  Sm  Sm6  1  0.750  0.859  0.261  1.0
  Sm  Sm7  1  0.750  0.878  0.921  1.0
  Ti  Ti8  1  0.250  0.124  0.422  1.0
  Ti  Ti9  1  0.750  0.376  0.922  1.0
  Ti  Ti10  1  0.250  0.624  0.078  1.0
  Ti  Ti11  1  0.750  0.876  0.578  1.0
  O  O12  1  0.750  0.090  0.171  1.0
  O  O13  1  0.750  0.088  0.454  1.0
  O  O14  1  0.750  0.102  0.648  1.0
  O  O15  1  0.750  0.156  0.991  1.0
  O  O16  1  0.250  0.255  0.324  1.0
  O  O17  1  0.750  0.245  0.824  1.0
  O  O18  1  0.250  0.344  0.491  1.0
  O  O19  1  0.250  0.398  0.148  1.0
  O  O20  1  0.250  0.412  0.954  1.0
  O  O21  1  0.250  0.410  0.671  1.0
  O  O22  1  0.750  0.590  0.329  1.0
  O  O23  1  0.750  0.588  0.046  1.0
  O  O24  1  0.750  0.602  0.852  1.0
  O  O25  1  0.750  0.656  0.509  1.0
  O  O26  1  0.250  0.755  0.176  1.0
  O  O27  1  0.750  0.745  0.676  1.0
  O  O28  1  0.250  0.844  0.009  1.0
  O  O29  1  0.250  0.898  0.352  1.0
  O  O30  1  0.250  0.912  0.546  1.0
  O  O31  1  0.250  0.910  0.829  1.0
[/CIF]
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The structure described by Sm2TiO5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(1), and three equivalent O(4) atoms. In the second Sm site, Sm(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form SmO6 octahedra that share corners with two equivalent Sm(2)O6 octahedra, corners with four equivalent Ti(1)O6 trigonal bipyramids, and edges with two equivalent Sm(2)O6 octahedra. The corner-sharing octahedral tilt angles are 67°. Ti(1) is bonded to one O(3), one O(4), one O(5), and three equivalent O(2) atoms to form distorted TiO6 trigonal bipyramids that share corners with four equivalent Sm(2)O6 octahedra, corners with two equivalent Ti(1)O6 trigonal bipyramids, and edges with two equivalent Ti(1)O6 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 50-64°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(3)Sm3Ti tetrahedra, corners with four equivalent O(4)Sm3Ti tetrahedra, corners with four equivalent O(1)Sm4 tetrahedra,  an edgeedge with one O(4)Sm3Ti tetrahedra, and edges with two equivalent O(3)Sm3Ti tetrahedra. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to three equivalent Ti(1) atoms. In the third O site, O(3) is bonded to one Sm(1), two equivalent Sm(2), and one Ti(1) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with four equivalent O(4)Sm3Ti tetrahedra, and edges with two equivalent O(1)Sm4 tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Sm(1) and one Ti(1) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(4)Sm3Ti tetrahedra, corners with four equivalent O(3)Sm3Ti tetrahedra, corners with four equivalent O(1)Sm4 tetrahedra,  an edgeedge with one O(1)Sm4 tetrahedra, and edges with two equivalent O(4)Sm3Ti tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Sm(2) and one Ti(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2TiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.697
_cell_length_b   7.630
_cell_length_c   15.897
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   448.396
_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
  Sm  Sm0  1  0.250  0.122  0.079  1.0
  Sm  Sm1  1  0.250  0.141  0.739  1.0
  Sm  Sm2  1  0.750  0.359  0.239  1.0
  Sm  Sm3  1  0.750  0.378  0.579  1.0
  Sm  Sm4  1  0.250  0.622  0.421  1.0
  Sm  Sm5  1  0.250  0.641  0.761  1.0
  Sm  Sm6  1  0.750  0.859  0.261  1.0
  Sm  Sm7  1  0.750  0.878  0.921  1.0
  Ti  Ti8  1  0.250  0.124  0.422  1.0
  Ti  Ti9  1  0.750  0.376  0.922  1.0
  Ti  Ti10  1  0.250  0.624  0.078  1.0
  Ti  Ti11  1  0.750  0.876  0.578  1.0
  O  O12  1  0.750  0.090  0.171  1.0
  O  O13  1  0.750  0.088  0.454  1.0
  O  O14  1  0.750  0.102  0.648  1.0
  O  O15  1  0.750  0.156  0.991  1.0
  O  O16  1  0.250  0.255  0.324  1.0
  O  O17  1  0.750  0.245  0.824  1.0
  O  O18  1  0.250  0.344  0.491  1.0
  O  O19  1  0.250  0.398  0.148  1.0
  O  O20  1  0.250  0.412  0.954  1.0
  O  O21  1  0.250  0.410  0.671  1.0
  O  O22  1  0.750  0.590  0.329  1.0
  O  O23  1  0.750  0.588  0.046  1.0
  O  O24  1  0.750  0.602  0.852  1.0
  O  O25  1  0.750  0.656  0.509  1.0
  O  O26  1  0.250  0.755  0.176  1.0
  O  O27  1  0.750  0.745  0.676  1.0
  O  O28  1  0.250  0.844  0.009  1.0
  O  O29  1  0.250  0.898  0.352  1.0
  O  O30  1  0.250  0.912  0.546  1.0
  O  O31  1  0.250  0.910  0.829  1.0
[/CIF]
.