The structure described by MgSm8Ti4O20 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(2), and two equivalent O(18) atoms. There are eight inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one O(17), one O(8), one O(9), two equivalent O(1), and two equivalent O(4) atoms. In the second Sm site, Sm(2) is bonded to one O(10), one O(19), one O(20), two equivalent O(3), and two equivalent O(6) atoms to form distorted SmO7 hexagonal pyramids that share corners with two equivalent Ti(2)O5 trigonal bipyramids, edges with two equivalent Sm(2)O7 hexagonal pyramids, and edges with two equivalent Ti(4)O5 trigonal bipyramids. In the third Sm site, Sm(3) is bonded to one O(1), one O(11), two equivalent O(5), and two equivalent O(8) atoms to form distorted SmO6 octahedra that share corners with two equivalent Ti(1)O5 trigonal bipyramids and edges with two equivalent Sm(3)O6 octahedra. In the fourth Sm site, Sm(4) is bonded in a 7-coordinate geometry to one O(16), one O(2), one O(3), two equivalent O(10), and two equivalent O(7) atoms. In the fifth Sm site, Sm(5) is bonded in a 7-coordinate geometry to one O(18), one O(5), one O(7), two equivalent O(11), and two equivalent O(14) atoms. In the sixth Sm site, Sm(6) is bonded in a 7-coordinate geometry to one O(10), one O(19), one O(20), two equivalent O(13), and two equivalent O(16) atoms. In the seventh Sm site, Sm(7) is bonded in a distorted see-saw-like geometry to one O(1), one O(11), two equivalent O(15), and two equivalent O(18) atoms. In the eighth Sm site, Sm(8) is bonded in a 7-coordinate geometry to one O(12), one O(13), one O(4), two equivalent O(17), and two equivalent O(20) atoms. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(18), one O(5), one O(7), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Sm(3)O6 octahedra and corners with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 58°. In the second Ti site, Ti(2) is bonded to one O(13), one O(4), one O(6), and two equivalent O(9) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Sm(2)O7 hexagonal pyramids and corners with two equivalent Ti(2)O5 trigonal bipyramids. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(15), one O(17), one O(8), one O(9), and two equivalent O(12) atoms. In the fourth Ti site, Ti(4) is bonded to one O(14), one O(16), one O(3), and two equivalent O(19) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Ti(4)O5 trigonal bipyramids and edges with two equivalent Sm(2)O7 hexagonal pyramids. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one Sm(3), one Sm(7), and two equivalent Sm(1) atoms to form distorted OSm4 tetrahedra that share corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(4)Sm3Ti tetrahedra, and edges with two equivalent O(8)Sm3Ti tetrahedra. In the second O site, O(2) is bonded to one Mg(1), one Sm(4), and two equivalent Ti(1) atoms to form distorted OSmMgTi2 trigonal pyramids that share  a cornercorner with one O(16)Sm3Ti tetrahedra,  a cornercorner with one O(3)Sm3Ti tetrahedra, corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra,  a cornercorner with one O(11)Sm4Mg trigonal bipyramid, corners with two equivalent O(2)SmMgTi2 trigonal pyramids, and edges with two equivalent O(7)Sm3Ti tetrahedra. In the third O site, O(3) is bonded to one Sm(4), two equivalent Sm(2), and one Ti(4) atom to form distorted OSm3Ti tetrahedra that share corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  a cornercorner with one O(2)SmMgTi2 trigonal pyramid, and edges with two equivalent O(10)Sm4 tetrahedra. In the fourth O site, O(4) is bonded to one Sm(8), two equivalent Sm(1), and one Ti(2) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  an edgeedge with one O(1)Sm4 tetrahedra, edges with two equivalent O(17)Sm3Ti tetrahedra, and edges with two equivalent O(9)SmTi3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Sm(5), two equivalent Sm(3), and one Ti(1) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(2)SmMgTi2 trigonal pyramids,  an edgeedge with one O(7)Sm3Ti tetrahedra,  an edgeedge with one O(8)Sm3Ti tetrahedra, and edges with two equivalent O(11)Sm4Mg trigonal bipyramids. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Sm(2) and one Ti(2) atom. In the seventh O site, O(7) is bonded to one Sm(5), two equivalent Sm(4), and one Ti(1) atom to form distorted OSm3Ti tetrahedra that share corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids,  an edgeedge with one O(5)Sm3Ti tetrahedra,  an edgeedge with one O(10)Sm4 tetrahedra, and edges with two equivalent O(2)SmMgTi2 trigonal pyramids. In the eighth O site, O(8) is bonded to one Sm(1), two equivalent Sm(3), and one Ti(3) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids,  an edgeedge with one O(5)Sm3Ti tetrahedra, edges with two equivalent O(1)Sm4 tetrahedra, and  an edgeedge with one O(9)SmTi3 trigonal pyramid. In the ninth O site, O(9) is bonded to one Sm(1), one Ti(3), and two equivalent Ti(2) atoms to form distorted OSmTi3 trigonal pyramids that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(8)Sm3Ti tetrahedra, and edges with two equivalent O(4)Sm3Ti tetrahedra. In the tenth O site, O(10) is bonded to one Sm(2), one Sm(6), and two equivalent Sm(4) atoms to form OSm4 tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra, corners with two equivalent O(2)SmMgTi2 trigonal pyramids,  an edgeedge with one O(7)Sm3Ti tetrahedra, edges with two equivalent O(16)Sm3Ti tetrahedra, and edges with two equivalent O(3)Sm3Ti tetrahedra. In the eleventh O site, O(11) is bonded to one Mg(1), one Sm(3), one Sm(7), and two equivalent Sm(5) atoms to form distorted OSm4Mg trigonal bipyramids that share corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids,  a cornercorner with one O(2)SmMgTi2 trigonal pyramid, and edges with two equivalent O(5)Sm3Ti tetrahedra. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Sm(8) and two equivalent Ti(3) atoms. In the thirteenth O site, O(13) is bonded to one Sm(8), two equivalent Sm(6), and one Ti(2) atom to form distorted OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(16)Sm3Ti tetrahedra, and edges with two equivalent O(20)Sm4 tetrahedra. In the fourteenth O site, O(14) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Sm(5), and one Ti(4) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to two equivalent Sm(7) and one Ti(3) atom. In the sixteenth O site, O(16) is bonded to one Sm(4), two equivalent Sm(6), and one Ti(4) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  a cornercorner with one O(2)SmMgTi2 trigonal pyramid,  an edgeedge with one O(13)Sm3Ti tetrahedra, and edges with two equivalent O(10)Sm4 tetrahedra. In the seventeenth O site, O(17) is bonded to one Sm(1), two equivalent Sm(8), and one Ti(3) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(20)Sm4 tetrahedra, and edges with two equivalent O(4)Sm3Ti tetrahedra. In the eighteenth O site, O(18) is bonded in a 6-coordinate geometry to two equivalent Mg(1), one Sm(5), two equivalent Sm(7), and one Ti(1) atom. In the nineteenth O site, O(19) is bonded in a 4-coordinate geometry to one Sm(2), one Sm(6), and two equivalent Ti(4) atoms. In the twentieth O site, O(20) is bonded to one Sm(2), one Sm(6), and two equivalent Sm(8) atoms to form OSm4 tetrahedra that share corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  an edgeedge with one O(17)Sm3Ti tetrahedra, and edges with two equivalent O(13)Sm3Ti tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm8MgTi4O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.889
_cell_length_b   3.741
_cell_length_c   15.987
_cell_angle_alpha   90.000
_cell_angle_beta   94.177
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   470.500
_cell_formula_units_Z   1
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  0.155  0.250  0.059  1.0
  Sm  Sm1  1  0.082  0.250  0.741  1.0
  Sm  Sm2  1  0.390  0.750  0.229  1.0
  Sm  Sm3  1  0.331  0.750  0.591  1.0
  Sm  Sm4  1  0.622  0.250  0.409  1.0
  Sm  Sm5  1  0.597  0.250  0.754  1.0
  Sm  Sm6  1  0.882  0.750  0.229  1.0
  Sm  Sm7  1  0.830  0.750  0.928  1.0
  Mg  Mg8  1  0.934  0.750  0.420  1.0
  Ti  Ti9  1  0.214  0.250  0.409  1.0
  Ti  Ti10  1  0.347  0.750  0.910  1.0
  Ti  Ti11  1  0.626  0.250  0.068  1.0
  Ti  Ti12  1  0.811  0.750  0.613  1.0
  O  O13  1  0.125  0.750  0.163  1.0
  O  O14  1  0.171  0.750  0.456  1.0
  O  O15  1  0.052  0.750  0.645  1.0
  O  O16  1  0.138  0.750  0.978  1.0
  O  O17  1  0.367  0.250  0.324  1.0
  O  O18  1  0.207  0.750  0.816  1.0
  O  O19  1  0.408  0.250  0.496  1.0
  O  O20  1  0.421  0.250  0.142  1.0
  O  O21  1  0.380  0.250  0.951  1.0
  O  O22  1  0.334  0.250  0.675  1.0
  O  O23  1  0.660  0.750  0.326  1.0
  O  O24  1  0.605  0.750  0.037  1.0
  O  O25  1  0.557  0.750  0.850  1.0
  O  O26  1  0.757  0.750  0.499  1.0
  O  O27  1  0.770  0.250  0.174  1.0
  O  O28  1  0.603  0.750  0.665  1.0
  O  O29  1  0.856  0.250  0.016  1.0
  O  O30  1  0.944  0.250  0.374  1.0
  O  O31  1  0.822  0.250  0.650  1.0
  O  O32  1  0.861  0.250  0.833  1.0
[/CIF]
.
The structure described by MgSm8Ti4O20 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(2), and two equivalent O(18) atoms. There are eight inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one O(17), one O(8), one O(9), two equivalent O(1), and two equivalent O(4) atoms. In the second Sm site, Sm(2) is bonded to one O(10), one O(19), one O(20), two equivalent O(3), and two equivalent O(6) atoms to form distorted SmO7 hexagonal pyramids that share corners with two equivalent Ti(2)O5 trigonal bipyramids, edges with two equivalent Sm(2)O7 hexagonal pyramids, and edges with two equivalent Ti(4)O5 trigonal bipyramids. In the third Sm site, Sm(3) is bonded to one O(1), one O(11), two equivalent O(5), and two equivalent O(8) atoms to form distorted SmO6 octahedra that share corners with two equivalent Ti(1)O5 trigonal bipyramids and edges with two equivalent Sm(3)O6 octahedra. In the fourth Sm site, Sm(4) is bonded in a 7-coordinate geometry to one O(16), one O(2), one O(3), two equivalent O(10), and two equivalent O(7) atoms. In the fifth Sm site, Sm(5) is bonded in a 7-coordinate geometry to one O(18), one O(5), one O(7), two equivalent O(11), and two equivalent O(14) atoms. In the sixth Sm site, Sm(6) is bonded in a 7-coordinate geometry to one O(10), one O(19), one O(20), two equivalent O(13), and two equivalent O(16) atoms. In the seventh Sm site, Sm(7) is bonded in a distorted see-saw-like geometry to one O(1), one O(11), two equivalent O(15), and two equivalent O(18) atoms. In the eighth Sm site, Sm(8) is bonded in a 7-coordinate geometry to one O(12), one O(13), one O(4), two equivalent O(17), and two equivalent O(20) atoms. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(18), one O(5), one O(7), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Sm(3)O6 octahedra and corners with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 58°. In the second Ti site, Ti(2) is bonded to one O(13), one O(4), one O(6), and two equivalent O(9) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Sm(2)O7 hexagonal pyramids and corners with two equivalent Ti(2)O5 trigonal bipyramids. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(15), one O(17), one O(8), one O(9), and two equivalent O(12) atoms. In the fourth Ti site, Ti(4) is bonded to one O(14), one O(16), one O(3), and two equivalent O(19) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Ti(4)O5 trigonal bipyramids and edges with two equivalent Sm(2)O7 hexagonal pyramids. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one Sm(3), one Sm(7), and two equivalent Sm(1) atoms to form distorted OSm4 tetrahedra that share corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(4)Sm3Ti tetrahedra, and edges with two equivalent O(8)Sm3Ti tetrahedra. In the second O site, O(2) is bonded to one Mg(1), one Sm(4), and two equivalent Ti(1) atoms to form distorted OSmMgTi2 trigonal pyramids that share  a cornercorner with one O(16)Sm3Ti tetrahedra,  a cornercorner with one O(3)Sm3Ti tetrahedra, corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra,  a cornercorner with one O(11)Sm4Mg trigonal bipyramid, corners with two equivalent O(2)SmMgTi2 trigonal pyramids, and edges with two equivalent O(7)Sm3Ti tetrahedra. In the third O site, O(3) is bonded to one Sm(4), two equivalent Sm(2), and one Ti(4) atom to form distorted OSm3Ti tetrahedra that share corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  a cornercorner with one O(2)SmMgTi2 trigonal pyramid, and edges with two equivalent O(10)Sm4 tetrahedra. In the fourth O site, O(4) is bonded to one Sm(8), two equivalent Sm(1), and one Ti(2) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  an edgeedge with one O(1)Sm4 tetrahedra, edges with two equivalent O(17)Sm3Ti tetrahedra, and edges with two equivalent O(9)SmTi3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Sm(5), two equivalent Sm(3), and one Ti(1) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(2)SmMgTi2 trigonal pyramids,  an edgeedge with one O(7)Sm3Ti tetrahedra,  an edgeedge with one O(8)Sm3Ti tetrahedra, and edges with two equivalent O(11)Sm4Mg trigonal bipyramids. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Sm(2) and one Ti(2) atom. In the seventh O site, O(7) is bonded to one Sm(5), two equivalent Sm(4), and one Ti(1) atom to form distorted OSm3Ti tetrahedra that share corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids,  an edgeedge with one O(5)Sm3Ti tetrahedra,  an edgeedge with one O(10)Sm4 tetrahedra, and edges with two equivalent O(2)SmMgTi2 trigonal pyramids. In the eighth O site, O(8) is bonded to one Sm(1), two equivalent Sm(3), and one Ti(3) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(5)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids,  an edgeedge with one O(5)Sm3Ti tetrahedra, edges with two equivalent O(1)Sm4 tetrahedra, and  an edgeedge with one O(9)SmTi3 trigonal pyramid. In the ninth O site, O(9) is bonded to one Sm(1), one Ti(3), and two equivalent Ti(2) atoms to form distorted OSmTi3 trigonal pyramids that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(8)Sm3Ti tetrahedra, and edges with two equivalent O(4)Sm3Ti tetrahedra. In the tenth O site, O(10) is bonded to one Sm(2), one Sm(6), and two equivalent Sm(4) atoms to form OSm4 tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra, corners with two equivalent O(2)SmMgTi2 trigonal pyramids,  an edgeedge with one O(7)Sm3Ti tetrahedra, edges with two equivalent O(16)Sm3Ti tetrahedra, and edges with two equivalent O(3)Sm3Ti tetrahedra. In the eleventh O site, O(11) is bonded to one Mg(1), one Sm(3), one Sm(7), and two equivalent Sm(5) atoms to form distorted OSm4Mg trigonal bipyramids that share corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(11)Sm4Mg trigonal bipyramids,  a cornercorner with one O(2)SmMgTi2 trigonal pyramid, and edges with two equivalent O(5)Sm3Ti tetrahedra. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Sm(8) and two equivalent Ti(3) atoms. In the thirteenth O site, O(13) is bonded to one Sm(8), two equivalent Sm(6), and one Ti(2) atom to form distorted OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(16)Sm3Ti tetrahedra, and edges with two equivalent O(20)Sm4 tetrahedra. In the fourteenth O site, O(14) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Sm(5), and one Ti(4) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to two equivalent Sm(7) and one Ti(3) atom. In the sixteenth O site, O(16) is bonded to one Sm(4), two equivalent Sm(6), and one Ti(4) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(7)Sm3Ti tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  a cornercorner with one O(2)SmMgTi2 trigonal pyramid,  an edgeedge with one O(13)Sm3Ti tetrahedra, and edges with two equivalent O(10)Sm4 tetrahedra. In the seventeenth O site, O(17) is bonded to one Sm(1), two equivalent Sm(8), and one Ti(3) atom to form OSm3Ti tetrahedra that share corners with two equivalent O(13)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(8)Sm3Ti tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra, corners with two equivalent O(9)SmTi3 trigonal pyramids,  an edgeedge with one O(20)Sm4 tetrahedra, and edges with two equivalent O(4)Sm3Ti tetrahedra. In the eighteenth O site, O(18) is bonded in a 6-coordinate geometry to two equivalent Mg(1), one Sm(5), two equivalent Sm(7), and one Ti(1) atom. In the nineteenth O site, O(19) is bonded in a 4-coordinate geometry to one Sm(2), one Sm(6), and two equivalent Ti(4) atoms. In the twentieth O site, O(20) is bonded to one Sm(2), one Sm(6), and two equivalent Sm(8) atoms to form OSm4 tetrahedra that share corners with two equivalent O(16)Sm3Ti tetrahedra, corners with two equivalent O(17)Sm3Ti tetrahedra, corners with two equivalent O(3)Sm3Ti tetrahedra, corners with two equivalent O(4)Sm3Ti tetrahedra, corners with two equivalent O(10)Sm4 tetrahedra, corners with two equivalent O(20)Sm4 tetrahedra,  an edgeedge with one O(17)Sm3Ti tetrahedra, and edges with two equivalent O(13)Sm3Ti tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm8MgTi4O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.889
_cell_length_b   3.741
_cell_length_c   15.987
_cell_angle_alpha   90.000
_cell_angle_beta   94.177
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   470.500
_cell_formula_units_Z   1
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  0.155  0.250  0.059  1.0
  Sm  Sm1  1  0.082  0.250  0.741  1.0
  Sm  Sm2  1  0.390  0.750  0.229  1.0
  Sm  Sm3  1  0.331  0.750  0.591  1.0
  Sm  Sm4  1  0.622  0.250  0.409  1.0
  Sm  Sm5  1  0.597  0.250  0.754  1.0
  Sm  Sm6  1  0.882  0.750  0.229  1.0
  Sm  Sm7  1  0.830  0.750  0.928  1.0
  Mg  Mg8  1  0.934  0.750  0.420  1.0
  Ti  Ti9  1  0.214  0.250  0.409  1.0
  Ti  Ti10  1  0.347  0.750  0.910  1.0
  Ti  Ti11  1  0.626  0.250  0.068  1.0
  Ti  Ti12  1  0.811  0.750  0.613  1.0
  O  O13  1  0.125  0.750  0.163  1.0
  O  O14  1  0.171  0.750  0.456  1.0
  O  O15  1  0.052  0.750  0.645  1.0
  O  O16  1  0.138  0.750  0.978  1.0
  O  O17  1  0.367  0.250  0.324  1.0
  O  O18  1  0.207  0.750  0.816  1.0
  O  O19  1  0.408  0.250  0.496  1.0
  O  O20  1  0.421  0.250  0.142  1.0
  O  O21  1  0.380  0.250  0.951  1.0
  O  O22  1  0.334  0.250  0.675  1.0
  O  O23  1  0.660  0.750  0.326  1.0
  O  O24  1  0.605  0.750  0.037  1.0
  O  O25  1  0.557  0.750  0.850  1.0
  O  O26  1  0.757  0.750  0.499  1.0
  O  O27  1  0.770  0.250  0.174  1.0
  O  O28  1  0.603  0.750  0.665  1.0
  O  O29  1  0.856  0.250  0.016  1.0
  O  O30  1  0.944  0.250  0.374  1.0
  O  O31  1  0.822  0.250  0.650  1.0
  O  O32  1  0.861  0.250  0.833  1.0
[/CIF]
.