A low-temperature redetermination of the monoclinic β-form of cyclooctaselenium
Tiina Maaninen; Jari Konu; Risto S. Laitinen; Acta Crystallographica Section E 60 (2004) o2235–o2237; doi:10.1107/S1600536804024055

data_2204812
_publ_section_title
;
 A low-temperature redetermination of the monoclinic \b-form of
 cyclooctaselenium
;
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2235
_journal_page_last               o2237
_journal_paper_doi               10.1107/S1600536804024055
_journal_volume                  60
_journal_year                    2004
_chemical_formula_iupac          Se8
_chemical_formula_moiety         Se8
_chemical_formula_structural     Se8
_chemical_formula_sum            Se8
_chemical_formula_weight         631.68
_chemical_name_systematic
;
beta-monoclinic cyclooctaselenium
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   none
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 92.95(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.2004(18)
_cell_length_b                   8.0000(16)
_cell_length_c                   12.735(3)
_cell_measurement_reflns_used    9298
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      26.00
_cell_measurement_theta_min      2.22
_cell_volume                     936.1(3)
_computing_cell_refinement       'DENZO--SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'KappaCCD Server Software (Nonius, 1997)'
_computing_data_reduction        DENZO--SMN
_computing_molecular_graphics    'DIAMOND (Brandenburg & Berndt, 1999)'
_computing_publication_material  'WINGX (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       '\f scans, and \w scans with \k offsets'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0777
_diffrn_reflns_av_sigmaI/netI    0.0501
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            9298
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.22
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    31.143
_exptl_absorpt_correction_T_max  0.2105
_exptl_absorpt_correction_T_min  0.0617
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(SHELXTL; Bruker, 2001)'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    4.482
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1088
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.05
_refine_diff_density_max         1.133
_refine_diff_density_min         -1.228
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.091
_refine_ls_matrix_type           full
_refine_ls_number_parameters     73
_refine_ls_number_reflns         1821
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.091
_refine_ls_R_factor_all          0.0584
_refine_ls_R_factor_gt           0.0400
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0413P)^2^+5.4999P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0874
_refine_ls_wR_factor_ref         0.0954
_reflns_number_gt                1463
_reflns_number_total             1821
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            wm6031.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2204812