The crystal structure described by CrO2 crystallizes in the monoclinic Cm space group. There are twelve inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one Cr(12)O4 tetrahedra, corners with two equivalent Cr(5)O4 tetrahedra,  an edgeedge with one Cr(11)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra, and edges with two equivalent Cr(1)O6 octahedra. In the second Cr site, Cr(2) is bonded to one O(4), one O(9), two equivalent O(5), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with three equivalent Cr(5)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(4)O6 octahedra. In the third Cr site, Cr(3) is bonded to one O(15), one O(7), and two equivalent O(10) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-56°. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(12), one O(14), one O(5), one O(7), and one O(9) atom to form CrO6 octahedra that share  a cornercorner with one Cr(3)O4 tetrahedra,  a cornercorner with one Cr(5)O4 tetrahedra, corners with two equivalent Cr(8)O4 tetrahedra,  an edgeedge with one Cr(2)O6 octahedra, and edges with two equivalent Cr(4)O6 octahedra. In the fifth Cr site, Cr(5) is bonded to one O(14), one O(4), and two equivalent O(6) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-59°. In the sixth Cr site, Cr(6) is bonded to one O(13), one O(21), and two equivalent O(17) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the seventh Cr site, Cr(7) is bonded to one O(10), one O(13), one O(15), one O(16), one O(18), and one O(20) atom to form CrO6 octahedra that share  a cornercorner with one Cr(6)O4 tetrahedra,  a cornercorner with one Cr(8)O4 tetrahedra, corners with two equivalent Cr(10)O4 tetrahedra, corners with two equivalent Cr(3)O4 tetrahedra, and edges with two equivalent Cr(7)O6 octahedra. In the eighth Cr site, Cr(8) is bonded to one O(11), one O(20), and two equivalent O(12) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the ninth Cr site, Cr(9) is bonded to one O(17), one O(19), one O(21), one O(22), one O(23), and one O(24) atom to form CrO6 octahedra that share  a cornercorner with one Cr(10)O4 tetrahedra, corners with two equivalent Cr(12)O4 tetrahedra, corners with two equivalent Cr(6)O4 tetrahedra,  an edgeedge with one Cr(11)O6 octahedra, and edges with two equivalent Cr(9)O6 octahedra. In the tenth Cr site, Cr(10) is bonded to one O(16), one O(24), and two equivalent O(18) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-55°. In the eleventh Cr site, Cr(11) is bonded to one O(22), one O(3), two equivalent O(1), and two equivalent O(23) atoms to form CrO6 octahedra that share corners with three equivalent Cr(12)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(9)O6 octahedra. In the twelfth Cr site, Cr(12) is bonded to one O(22), one O(8), and two equivalent O(23) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-61°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Cr(1) and one Cr(11) atom. In the second O site, O(2) is bonded in a water-like geometry to two equivalent Cr(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Cr(11) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal pyramidal geometry to one Cr(2), one Cr(5), and two equivalent Cr(1) atoms. In the fifth O site, O(5) is bonded in a water-like geometry to one Cr(2) and one Cr(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one Cr(5) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cr(3) and two equivalent Cr(4) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Cr(12) and two equivalent Cr(1) atoms. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Cr(2) and two equivalent Cr(4) atoms. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cr(3) and one Cr(7) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Cr(8) and two equivalent Cr(4) atoms. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Cr(4) and one Cr(8) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Cr(6) and two equivalent Cr(7) atoms. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Cr(5) and two equivalent Cr(4) atoms. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Cr(3) and two equivalent Cr(7) atoms. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Cr(10) and two equivalent Cr(7) atoms. In the seventeenth O site, O(17) is bonded in a distorted bent 120 degrees geometry to one Cr(6) and one Cr(9) atom. In the eighteenth O site, O(18) is bonded in a bent 120 degrees geometry to one Cr(10) and one Cr(7) atom. In the nineteenth O site, O(19) is bonded in a water-like geometry to two equivalent Cr(9) atoms. In the twentieth O site, O(20) is bonded in a distorted trigonal planar geometry to one Cr(8) and two equivalent Cr(7) atoms. In the twenty-first O site, O(21) is bonded in a distorted trigonal planar geometry to one Cr(6) and two equivalent Cr(9) atoms. In the twenty-second O site, O(22) is bonded in a rectangular see-saw-like geometry to one Cr(11), one Cr(12), and two equivalent Cr(9) atoms. In the twenty-third O site, O(23) is bonded in a distorted trigonal planar geometry to one Cr(11), one Cr(12), and one Cr(9) atom. In the twenty-fourth O site, O(24) is bonded in a distorted trigonal planar geometry to one Cr(10) and two equivalent Cr(9) atoms. is represented by the CIF file [CIF]
data_CrO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.806
_cell_length_b   6.003
_cell_length_c   23.352
_cell_angle_alpha   59.062
_cell_angle_beta   59.337
_cell_angle_gamma   58.874
_symmetry_Int_Tables_number   1
_cell_volume   563.567
_cell_formula_units_Z   16
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
  Cr  Cr0  1  0.489  0.488  0.126  1.0
  Cr  Cr1  1  0.483  0.491  0.259  1.0
  Cr  Cr2  1  0.489  0.018  0.126  1.0
  Cr  Cr3  1  0.128  0.118  0.534  1.0
  Cr  Cr4  1  0.499  0.496  0.376  1.0
  Cr  Cr5  1  0.858  0.880  0.220  1.0
  Cr  Cr6  1  0.128  0.130  0.778  1.0
  Cr  Cr7  1  0.499  1.000  0.376  1.0
  Cr  Cr8  1  0.503  0.501  0.624  1.0
  Cr  Cr9  1  0.878  0.877  0.467  1.0
  Cr  Cr10  1  0.503  0.000  0.624  1.0
  Cr  Cr11  1  0.495  0.019  0.872  1.0
  Cr  Cr12  1  0.495  0.499  0.872  1.0
  Cr  Cr13  1  0.875  0.878  0.717  1.0
  Cr  Cr14  1  0.493  0.494  0.005  1.0
  Cr  Cr15  1  0.856  0.879  0.972  1.0
  O  O16  1  0.296  0.252  0.062  1.0
  O  O17  1  0.290  0.247  0.179  1.0
  O  O18  1  0.296  0.705  0.062  1.0
  O  O19  1  0.718  0.257  0.067  1.0
  O  O20  1  0.258  0.746  0.188  1.0
  O  O21  1  0.290  0.250  0.314  1.0
  O  O22  1  0.719  0.257  0.192  1.0
  O  O23  1  0.271  0.233  0.441  1.0
  O  O24  1  0.290  0.702  0.314  1.0
  O  O25  1  0.717  0.759  0.066  1.0
  O  O26  1  0.710  0.255  0.320  1.0
  O  O27  1  0.719  0.757  0.192  1.0
  O  O28  1  0.253  0.229  0.563  1.0
  O  O29  1  0.250  0.758  0.433  1.0
  O  O30  1  0.756  0.218  0.438  1.0
  O  O31  1  0.274  0.245  0.684  1.0
  O  O32  1  0.253  0.766  0.563  1.0
  O  O33  1  0.725  0.753  0.317  1.0
  O  O34  1  0.743  0.244  0.567  1.0
  O  O35  1  0.756  0.775  0.438  1.0
  O  O36  1  0.263  0.756  0.681  1.0
  O  O37  1  0.255  0.225  0.810  1.0
  O  O38  1  0.752  0.230  0.687  1.0
  O  O39  1  0.283  0.271  0.919  1.0
  O  O40  1  0.255  0.782  0.810  1.0
  O  O41  1  0.736  0.759  0.561  1.0
  O  O42  1  0.749  0.246  0.815  1.0
  O  O43  1  0.752  0.771  0.687  1.0
  O  O44  1  0.263  0.750  0.934  1.0
  O  O45  1  0.717  0.260  0.939  1.0
  O  O46  1  0.728  0.763  0.812  1.0
  O  O47  1  0.717  0.768  0.939  1.0
[/CIF]
.
The crystal structure described by CrO2 crystallizes in the monoclinic Cm space group. There are twelve inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one Cr(12)O4 tetrahedra, corners with two equivalent Cr(5)O4 tetrahedra,  an edgeedge with one Cr(11)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra, and edges with two equivalent Cr(1)O6 octahedra. In the second Cr site, Cr(2) is bonded to one O(4), one O(9), two equivalent O(5), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with three equivalent Cr(5)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(4)O6 octahedra. In the third Cr site, Cr(3) is bonded to one O(15), one O(7), and two equivalent O(10) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-56°. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(12), one O(14), one O(5), one O(7), and one O(9) atom to form CrO6 octahedra that share  a cornercorner with one Cr(3)O4 tetrahedra,  a cornercorner with one Cr(5)O4 tetrahedra, corners with two equivalent Cr(8)O4 tetrahedra,  an edgeedge with one Cr(2)O6 octahedra, and edges with two equivalent Cr(4)O6 octahedra. In the fifth Cr site, Cr(5) is bonded to one O(14), one O(4), and two equivalent O(6) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-59°. In the sixth Cr site, Cr(6) is bonded to one O(13), one O(21), and two equivalent O(17) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the seventh Cr site, Cr(7) is bonded to one O(10), one O(13), one O(15), one O(16), one O(18), and one O(20) atom to form CrO6 octahedra that share  a cornercorner with one Cr(6)O4 tetrahedra,  a cornercorner with one Cr(8)O4 tetrahedra, corners with two equivalent Cr(10)O4 tetrahedra, corners with two equivalent Cr(3)O4 tetrahedra, and edges with two equivalent Cr(7)O6 octahedra. In the eighth Cr site, Cr(8) is bonded to one O(11), one O(20), and two equivalent O(12) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the ninth Cr site, Cr(9) is bonded to one O(17), one O(19), one O(21), one O(22), one O(23), and one O(24) atom to form CrO6 octahedra that share  a cornercorner with one Cr(10)O4 tetrahedra, corners with two equivalent Cr(12)O4 tetrahedra, corners with two equivalent Cr(6)O4 tetrahedra,  an edgeedge with one Cr(11)O6 octahedra, and edges with two equivalent Cr(9)O6 octahedra. In the tenth Cr site, Cr(10) is bonded to one O(16), one O(24), and two equivalent O(18) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-55°. In the eleventh Cr site, Cr(11) is bonded to one O(22), one O(3), two equivalent O(1), and two equivalent O(23) atoms to form CrO6 octahedra that share corners with three equivalent Cr(12)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(9)O6 octahedra. In the twelfth Cr site, Cr(12) is bonded to one O(22), one O(8), and two equivalent O(23) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-61°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Cr(1) and one Cr(11) atom. In the second O site, O(2) is bonded in a water-like geometry to two equivalent Cr(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Cr(11) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal pyramidal geometry to one Cr(2), one Cr(5), and two equivalent Cr(1) atoms. In the fifth O site, O(5) is bonded in a water-like geometry to one Cr(2) and one Cr(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one Cr(5) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cr(3) and two equivalent Cr(4) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Cr(12) and two equivalent Cr(1) atoms. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Cr(2) and two equivalent Cr(4) atoms. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cr(3) and one Cr(7) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Cr(8) and two equivalent Cr(4) atoms. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Cr(4) and one Cr(8) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Cr(6) and two equivalent Cr(7) atoms. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Cr(5) and two equivalent Cr(4) atoms. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Cr(3) and two equivalent Cr(7) atoms. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Cr(10) and two equivalent Cr(7) atoms. In the seventeenth O site, O(17) is bonded in a distorted bent 120 degrees geometry to one Cr(6) and one Cr(9) atom. In the eighteenth O site, O(18) is bonded in a bent 120 degrees geometry to one Cr(10) and one Cr(7) atom. In the nineteenth O site, O(19) is bonded in a water-like geometry to two equivalent Cr(9) atoms. In the twentieth O site, O(20) is bonded in a distorted trigonal planar geometry to one Cr(8) and two equivalent Cr(7) atoms. In the twenty-first O site, O(21) is bonded in a distorted trigonal planar geometry to one Cr(6) and two equivalent Cr(9) atoms. In the twenty-second O site, O(22) is bonded in a rectangular see-saw-like geometry to one Cr(11), one Cr(12), and two equivalent Cr(9) atoms. In the twenty-third O site, O(23) is bonded in a distorted trigonal planar geometry to one Cr(11), one Cr(12), and one Cr(9) atom. In the twenty-fourth O site, O(24) is bonded in a distorted trigonal planar geometry to one Cr(10) and two equivalent Cr(9) atoms. is represented by the CIF file [CIF]
data_CrO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.806
_cell_length_b   6.003
_cell_length_c   23.352
_cell_angle_alpha   59.062
_cell_angle_beta   59.337
_cell_angle_gamma   58.874
_symmetry_Int_Tables_number   1
_cell_volume   563.567
_cell_formula_units_Z   16
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
  Cr  Cr0  1  0.489  0.488  0.126  1.0
  Cr  Cr1  1  0.483  0.491  0.259  1.0
  Cr  Cr2  1  0.489  0.018  0.126  1.0
  Cr  Cr3  1  0.128  0.118  0.534  1.0
  Cr  Cr4  1  0.499  0.496  0.376  1.0
  Cr  Cr5  1  0.858  0.880  0.220  1.0
  Cr  Cr6  1  0.128  0.130  0.778  1.0
  Cr  Cr7  1  0.499  1.000  0.376  1.0
  Cr  Cr8  1  0.503  0.501  0.624  1.0
  Cr  Cr9  1  0.878  0.877  0.467  1.0
  Cr  Cr10  1  0.503  0.000  0.624  1.0
  Cr  Cr11  1  0.495  0.019  0.872  1.0
  Cr  Cr12  1  0.495  0.499  0.872  1.0
  Cr  Cr13  1  0.875  0.878  0.717  1.0
  Cr  Cr14  1  0.493  0.494  0.005  1.0
  Cr  Cr15  1  0.856  0.879  0.972  1.0
  O  O16  1  0.296  0.252  0.062  1.0
  O  O17  1  0.290  0.247  0.179  1.0
  O  O18  1  0.296  0.705  0.062  1.0
  O  O19  1  0.718  0.257  0.067  1.0
  O  O20  1  0.258  0.746  0.188  1.0
  O  O21  1  0.290  0.250  0.314  1.0
  O  O22  1  0.719  0.257  0.192  1.0
  O  O23  1  0.271  0.233  0.441  1.0
  O  O24  1  0.290  0.702  0.314  1.0
  O  O25  1  0.717  0.759  0.066  1.0
  O  O26  1  0.710  0.255  0.320  1.0
  O  O27  1  0.719  0.757  0.192  1.0
  O  O28  1  0.253  0.229  0.563  1.0
  O  O29  1  0.250  0.758  0.433  1.0
  O  O30  1  0.756  0.218  0.438  1.0
  O  O31  1  0.274  0.245  0.684  1.0
  O  O32  1  0.253  0.766  0.563  1.0
  O  O33  1  0.725  0.753  0.317  1.0
  O  O34  1  0.743  0.244  0.567  1.0
  O  O35  1  0.756  0.775  0.438  1.0
  O  O36  1  0.263  0.756  0.681  1.0
  O  O37  1  0.255  0.225  0.810  1.0
  O  O38  1  0.752  0.230  0.687  1.0
  O  O39  1  0.283  0.271  0.919  1.0
  O  O40  1  0.255  0.782  0.810  1.0
  O  O41  1  0.736  0.759  0.561  1.0
  O  O42  1  0.749  0.246  0.815  1.0
  O  O43  1  0.752  0.771  0.687  1.0
  O  O44  1  0.263  0.750  0.934  1.0
  O  O45  1  0.717  0.260  0.939  1.0
  O  O46  1  0.728  0.763  0.812  1.0
  O  O47  1  0.717  0.768  0.939  1.0
[/CIF]
.