Crystal structure of bis(η^5^-6,6-dimethylcyclohexadienyl)chromium, Cr(C~8~H~11~)~2~
Ernst, Richard D.; Basta, Rehan; Arif, Atta M.; Zeitschrift für Kristallographie - New Crystal Structures 222 (2007) 335–336; doi:

data_8102168
_publ_section_title
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Crystal structure of bis(\h^5^-6,6-dimethylcyclohexadienyl)chromium, 
Cr(C~8~H~11~)~2~
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_journal_issue                   3
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              335
_journal_page_last               336
_journal_volume                  222
_journal_year                    2007
_chemical_formula_structural     Cr(C8H11)2
_chemical_formula_sum            'C16 H22 Cr'
_chemical_formula_weight         266.34
_chemical_name_systematic
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bis(\h^5^-6,6-dimethylcyclohexadienyl)chromium
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.6112(2)
_cell_length_b                   9.2521(4)
_cell_length_c                   20.2174(9)
_cell_measurement_temperature    200.00(10)
_cell_volume                     1423.70(10)
_computing_cell_refinement       DENZO-SMN
_computing_data_collection       'Nonius COLLECT'
_computing_data_reduction        DENZO-SMN
_computing_molecular_graphics    'WinGX, Ortep3'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    SIR97
_diffrn_ambient_temperature      200.00(10)
_diffrn_measured_fraction_theta_full 0.919
_diffrn_measured_fraction_theta_max 0.919
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       phi
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0653
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            5004
_diffrn_reflns_theta_full        33.71
_diffrn_reflns_theta_max         33.71
_diffrn_reflns_theta_min         3.61
_diffrn_standards_decay_%        <2.0
_exptl_absorpt_coefficient_mu    0.780
_exptl_absorpt_correction_type   SCALEPACK
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.243
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             568
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.305
_refine_diff_density_rms         0.054
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.02(2)
_refine_ls_extinction_coef       0.0067(13)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     243
_refine_ls_number_reflns         5004
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0837
_refine_ls_R_factor_gt           0.0456
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0236P)^2^+0.1368P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0739
_refine_ls_wR_factor_ref         0.0847
_reflns_number_gt                3441
_reflns_number_total             5004
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            1267-2072.cff
_cod_data_source_block           shelxl
_cod_depositor_comments
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The following automatic conversions were performed:

'_cell_measurement_temperature' value '200(0.1)' was changed to
'200.00(10)' - precision was
estimated.

'_diffrn_ambient_temperature' value '200(0.1)' was
changed to '200.00(10)' - precision was estimated.

Automatic conversion script
Id: cif_fix_values 1569 2011-02-09 13:29:24Z adriana 
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_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               8102168