The crystal structure described by Lu2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(3) atoms. In the second Lu site, Lu(2) is bonded to one O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form LuO7 pentagonal bipyramids that share corners with four equivalent Si(1)O4 tetrahedra, edges with three equivalent Lu(2)O7 pentagonal bipyramids, and  an edgeedge with one 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 corners with four equivalent Lu(2)O7 pentagonal bipyramids and  an edgeedge with one Lu(2)O7 pentagonal bipyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Lu(2) and three equivalent Lu(1) atoms to form a mixture of edge and corner-sharing OLu4 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Lu(2) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Lu(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Lu(1), two equivalent Lu(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Lu(2) and one Si(1) atom. is represented by the CIF file [CIF]
data_Lu2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.555
_cell_length_b   6.544
_cell_length_c   8.974
_cell_angle_alpha   90.000
_cell_angle_beta   100.022
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   379.084
_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
  Lu  Lu0  1  0.274  0.118  0.465  1.0
  Lu  Lu1  1  0.226  0.618  0.535  1.0
  Lu  Lu2  1  0.726  0.882  0.535  1.0
  Lu  Lu3  1  0.774  0.382  0.465  1.0
  Lu  Lu4  1  0.990  0.642  0.852  1.0
  Lu  Lu5  1  0.510  0.142  0.148  1.0
  Lu  Lu6  1  0.010  0.358  0.148  1.0
  Lu  Lu7  1  0.490  0.858  0.852  1.0
  Si  Si8  1  0.987  0.099  0.798  1.0
  Si  Si9  1  0.513  0.599  0.202  1.0
  Si  Si10  1  0.013  0.901  0.202  1.0
  Si  Si11  1  0.487  0.401  0.798  1.0
  O  O12  1  0.420  0.878  0.606  1.0
  O  O13  1  0.080  0.378  0.394  1.0
  O  O14  1  0.580  0.122  0.394  1.0
  O  O15  1  0.920  0.622  0.606  1.0
  O  O16  1  0.994  0.300  0.901  1.0
  O  O17  1  0.506  0.800  0.099  1.0
  O  O18  1  0.006  0.700  0.099  1.0
  O  O19  1  0.494  0.200  0.901  1.0
  O  O20  1  0.965  0.148  0.614  1.0
  O  O21  1  0.535  0.648  0.386  1.0
  O  O22  1  0.035  0.852  0.386  1.0
  O  O23  1  0.465  0.352  0.614  1.0
  O  O24  1  0.289  0.560  0.790  1.0
  O  O25  1  0.211  0.060  0.210  1.0
  O  O26  1  0.711  0.440  0.210  1.0
  O  O27  1  0.789  0.940  0.790  1.0
  O  O28  1  0.670  0.566  0.851  1.0
  O  O29  1  0.830  0.066  0.149  1.0
  O  O30  1  0.330  0.434  0.149  1.0
  O  O31  1  0.170  0.934  0.851  1.0
[/CIF]
.
The crystal structure described by Lu2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(3) atoms. In the second Lu site, Lu(2) is bonded to one O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form LuO7 pentagonal bipyramids that share corners with four equivalent Si(1)O4 tetrahedra, edges with three equivalent Lu(2)O7 pentagonal bipyramids, and  an edgeedge with one 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 corners with four equivalent Lu(2)O7 pentagonal bipyramids and  an edgeedge with one Lu(2)O7 pentagonal bipyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Lu(2) and three equivalent Lu(1) atoms to form a mixture of edge and corner-sharing OLu4 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Lu(2) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Lu(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Lu(1), two equivalent Lu(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Lu(2) and one Si(1) atom. is represented by the CIF file [CIF]
data_Lu2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.555
_cell_length_b   6.544
_cell_length_c   8.974
_cell_angle_alpha   90.000
_cell_angle_beta   100.022
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   379.084
_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
  Lu  Lu0  1  0.274  0.118  0.465  1.0
  Lu  Lu1  1  0.226  0.618  0.535  1.0
  Lu  Lu2  1  0.726  0.882  0.535  1.0
  Lu  Lu3  1  0.774  0.382  0.465  1.0
  Lu  Lu4  1  0.990  0.642  0.852  1.0
  Lu  Lu5  1  0.510  0.142  0.148  1.0
  Lu  Lu6  1  0.010  0.358  0.148  1.0
  Lu  Lu7  1  0.490  0.858  0.852  1.0
  Si  Si8  1  0.987  0.099  0.798  1.0
  Si  Si9  1  0.513  0.599  0.202  1.0
  Si  Si10  1  0.013  0.901  0.202  1.0
  Si  Si11  1  0.487  0.401  0.798  1.0
  O  O12  1  0.420  0.878  0.606  1.0
  O  O13  1  0.080  0.378  0.394  1.0
  O  O14  1  0.580  0.122  0.394  1.0
  O  O15  1  0.920  0.622  0.606  1.0
  O  O16  1  0.994  0.300  0.901  1.0
  O  O17  1  0.506  0.800  0.099  1.0
  O  O18  1  0.006  0.700  0.099  1.0
  O  O19  1  0.494  0.200  0.901  1.0
  O  O20  1  0.965  0.148  0.614  1.0
  O  O21  1  0.535  0.648  0.386  1.0
  O  O22  1  0.035  0.852  0.386  1.0
  O  O23  1  0.465  0.352  0.614  1.0
  O  O24  1  0.289  0.560  0.790  1.0
  O  O25  1  0.211  0.060  0.210  1.0
  O  O26  1  0.711  0.440  0.210  1.0
  O  O27  1  0.789  0.940  0.790  1.0
  O  O28  1  0.670  0.566  0.851  1.0
  O  O29  1  0.830  0.066  0.149  1.0
  O  O30  1  0.330  0.434  0.149  1.0
  O  O31  1  0.170  0.934  0.851  1.0
[/CIF]
.