 
data_x1
 
_audit_creation_method            SHELXL-2014/6
_chemical_name_systematic         ?
_chemical_name_common             ?
_chemical_melting_point           ?
_chemical_formula_moiety          ?
_chemical_formula_sum
 'Se2 Si' 
_chemical_formula_weight          186.01

loop_
 _atom_type_symbol
 _atom_type_description
 _atom_type_scat_dispersion_real
 _atom_type_scat_dispersion_imag
 _atom_type_scat_source
 'Se'  'Se'  -0.0929   2.2259
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
 'Si'  'Si'   0.0817   0.0704
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
 
_space_group_crystal_system       monoclinic
_space_group_IT_number            14
_space_group_name_H-M_alt         'P 21/c'
_space_group_name_Hall            '-P 2ybc'
 
_shelx_space_group_comment
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
 
loop_
 _space_group_symop_operation_xyz
 'x, y, z'
 '-x, y+1/2, -z+1/2'
 '-x, -y, -z'
 'x, -y-1/2, z-1/2'
 
_cell_length_a                    6.250(2)
_cell_length_b                    16.916(6)
_cell_length_c                    6.134(2)
_cell_angle_alpha                 90
_cell_angle_beta                  100.646(5)
_cell_angle_gamma                 90
_cell_volume                      637.4(4)
_cell_formula_units_Z             8
_cell_measurement_temperature     90(2)
_cell_measurement_reflns_used     8294
_cell_measurement_theta_min       2.408
_cell_measurement_theta_max       27.996
 
_exptl_crystal_description        Block
_exptl_crystal_colour             "brown-red"
_exptl_crystal_density_meas       ?
_exptl_crystal_density_method     ?
_exptl_crystal_density_diffrn     3.877          
_exptl_crystal_F_000              656
_exptl_transmission_factor_min    0.396
_exptl_transmission_factor_max    0.786
_exptl_crystal_size_max           0.04
_exptl_crystal_size_mid           0.03
_exptl_crystal_size_min           0.02
_exptl_absorpt_coefficient_mu     23.259
_shelx_estimated_absorpt_T_min    ?
_shelx_estimated_absorpt_T_max    ?
_exptl_absorpt_correction_type    multi-scan 
_exptl_absorpt_correction_T_min   0.421
_exptl_absorpt_correction_T_max   0.625
_exptl_absorpt_process_details    ?
_exptl_absorpt_special_details    ?
_diffrn_ambient_temperature       90(2)
_diffrn_radiation_wavelength      0.71073
_diffrn_radiation_type            MoK\a
_diffrn_radiation_source          'fine-focus sealed tube' 
_diffrn_radiation_monochromator   graphite 
_diffrn_measurement_device_type    'Bruker APEX II CCD area-detector' 
_diffrn_measurement_method       'profile data from ω scans'
_diffrn_reflns_number             8294
_diffrn_reflns_av_unetI/netI      0.0581
_diffrn_reflns_av_R_equivalents   0.0695
_diffrn_reflns_limit_h_min        -8
_diffrn_reflns_limit_h_max        8
_diffrn_reflns_limit_k_min        -22
_diffrn_reflns_limit_k_max        22
_diffrn_reflns_limit_l_min        -8
_diffrn_reflns_limit_l_max        8
_diffrn_reflns_theta_min          2.408
_diffrn_reflns_theta_max          27.996
_diffrn_reflns_theta_full         25.242
_diffrn_measured_fraction_theta_max   0.999
_diffrn_measured_fraction_theta_full  0.999
_diffrn_reflns_Laue_measured_fraction_max    0.999
_diffrn_reflns_Laue_measured_fraction_full   0.999
_diffrn_reflns_point_group_measured_fraction_max   0.999
_diffrn_reflns_point_group_measured_fraction_full  0.999
_reflns_number_total              1537
_reflns_number_gt                 879
_reflns_threshold_expression      'I > 2σ(I)'
_reflns_Friedel_coverage          0.000
_reflns_Friedel_fraction_max      .
_reflns_Friedel_fraction_full     .
 
_reflns_special_details
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
 
_computing_data_collection        'SMART V5.625 (Bruker, 2000)'
_computing_cell_refinement        'SMART V5.625 (Bruker, 2000)'
_computing_data_reduction         'SAINT V6.32 (Bruker, 2001)'
_computing_structure_solution     'SHELXS-97 (Sheldrick, 1990)'
_computing_structure_refinement   'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics     ?
_computing_publication_material   'SHELXL-97 (Sheldrick, 1997)' 
_refine_special_details           ?
_refine_ls_structure_factor_coef  Fsqd
_refine_ls_matrix_type            full
_refine_ls_weighting_scheme       calc
_refine_ls_weighting_details
'w=1/[σ²(Fo²)+(0.0689P)²] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_primary      ?
_atom_sites_solution_secondary    ?
_atom_sites_solution_hydrogens    .
_refine_ls_hydrogen_treatment     undef
_refine_ls_extinction_method      SHELXL
_refine_ls_extinction_coef        0.0009(3)
_refine_ls_extinction_expression
 'Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^'
_refine_ls_number_reflns          1537
_refine_ls_number_parameters      56
_refine_ls_number_restraints      0
_refine_ls_R_factor_all           0.0929
_refine_ls_R_factor_gt            0.0472
_refine_ls_wR_factor_ref          0.1475
_refine_ls_wR_factor_gt           0.1212
_refine_ls_goodness_of_fit_ref    0.992
_refine_ls_restrained_S_all       0.992
_refine_ls_shift/su_max           0.000
_refine_ls_shift/su_mean          0.000
 
loop_
 _atom_site_label
 _atom_site_type_symbol
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_U_iso_or_equiv
 _atom_site_adp_type
 _atom_site_occupancy
 _atom_site_site_symmetry_order  
 _atom_site_calc_flag
 _atom_site_refinement_flags_posn
 _atom_site_refinement_flags_adp
 _atom_site_refinement_flags_occupancy
 _atom_site_disorder_assembly
 _atom_site_disorder_group
Si1 Si 0.1245(5) 0.06441(13) 0.1241(4) 0.0156(6) Uani 1 1 d . . . . .
Si2 Si 0.3688(5) 0.19512(13) 0.3645(4) 0.0165(6) Uani 1 1 d . . . . .
Se1 Se 0.00396(15) 0.18101(5) 0.24442(13) 0.0164(3) Uani 1 1 d . . . . .
Se2 Se 0.49657(15) 0.30839(5) 0.23703(14) 0.0163(3) Uani 1 1 d . . . . .
Se3 Se 0.48880(15) 0.07832(6) 0.24803(14) 0.0170(3) Uani 1 1 d . . . . .
Se4 Se 0.00845(15) 0.45134(6) 0.25241(14) 0.0170(3) Uani 1 1 d . . . . .
 
 
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
 
loop_
 _geom_bond_atom_site_label_1
 _geom_bond_atom_site_label_2
 _geom_bond_distance
 _geom_bond_site_symmetry_2
 _geom_bond_publ_flag
Si1 Se4 2.271(3) 2_545 ?
Si1 Se3 2.276(3) . ?
Si1 Se4 2.277(3) 4_565 ?
Si1 Se1 2.282(3) . ?
Si2 Se2 2.270(3) . ?
Si2 Se3 2.275(3) . ?
Si2 Se1 2.276(3) . ?
Si2 Se2 2.278(3) 4_566 ?
Se2 Si2 2.278(3) 4_565 ?
Se4 Si1 2.271(3) 2 ?
Se4 Si1 2.277(3) 4_566 ?
 
loop_
 _geom_angle_atom_site_label_1
 _geom_angle_atom_site_label_2
 _geom_angle_atom_site_label_3
 _geom_angle
 _geom_angle_site_symmetry_1
 _geom_angle_site_symmetry_3
 _geom_angle_publ_flag
Se4 Si1 Se3 112.39(12) 2_545 . ?
Se4 Si1 Se4 99.61(10) 2_545 4_565 ?
Se3 Si1 Se4 117.44(12) . 4_565 ?
Se4 Si1 Se1 117.19(12) 2_545 . ?
Se3 Si1 Se1 99.92(10) . . ?
Se4 Si1 Se1 111.22(12) 4_565 . ?
Se2 Si2 Se3 117.89(12) . . ?
Se2 Si2 Se1 111.86(11) . . ?
Se3 Si2 Se1 100.15(10) . . ?
Se2 Si2 Se2 106.68(11) . 4_566 ?
Se3 Si2 Se2 102.57(10) . 4_566 ?
Se1 Si2 Se2 117.81(12) . 4_566 ?
Si2 Se1 Si1 79.88(10) . . ?
Si2 Se2 Si2 104.07(9) . 4_565 ?
Si2 Se3 Si1 80.04(10) . . ?
Si1 Se4 Si1 80.38(10) 2 4_566 ?
 
_refine_diff_density_max    2.273
_refine_diff_density_min   -1.514
_refine_diff_density_rms    0.322

_shelxl_version_number 2014/6



