Dimethylcalcium.
Wolf, Benjamin M.; Stuhl, Christoph; Maichle-Mössmer, Cäcilia; Anwander, Reiner; Journal of the American Chemical Society 140 (2018) 2373–2383; doi:10.1021/jacs.7b12984

data_4131918
_publ_section_title
;
 Dimethylcalcium.
;
_journal_issue                   6
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              2373
_journal_page_last               2383
_journal_paper_doi               10.1021/jacs.7b12984
_journal_volume                  140
_journal_year                    2018
_chemical_formula_sum            'C55 H108 Ca2 O6'
_chemical_formula_weight         945.57
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 111.5000(10)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   12.3787(12)
_cell_length_b                   19.6198(18)
_cell_length_c                   12.7078(12)
_cell_measurement_reflns_used    9797
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      29.99
_cell_measurement_theta_min      2.222
_cell_volume                     2871.6(5)
_computing_cell_refinement       'SAINT V8.37A (Bruker AXS Inc., 2015)'
_computing_data_collection       'Bruker Apex3'
_computing_data_reduction        'SAINT V8.37A (Bruker AXS Inc., 2015)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'XT, VERSION 2014/5'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Smart Apex III Duo'
_diffrn_measurement_method       omega/phi-scans
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0526
_diffrn_reflns_av_unetI/netI     0.0426
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            58747
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.700
_diffrn_reflns_theta_min         2.011
_diffrn_source                   Imus-tube
_exptl_absorpt_coefficient_mu    0.242
_exptl_absorpt_correction_T_max  0.7460
_exptl_absorpt_correction_T_min  0.6818
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.094
_exptl_crystal_description       block
_exptl_crystal_F_000             1052
_exptl_crystal_size_max          0.444
_exptl_crystal_size_mid          0.253
_exptl_crystal_size_min          0.226
_refine_diff_density_max         0.568
_refine_diff_density_min         -0.287
_refine_diff_density_rms         0.050
_refine_ls_abs_structure_details
;
 Flack x determined using 6444 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.010(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     662
_refine_ls_number_reflns         14853
_refine_ls_number_restraints     437
_refine_ls_restrained_S_all      1.074
_refine_ls_R_factor_all          0.0427
_refine_ls_R_factor_gt           0.0398
_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^)+(0.0583P)^2^+0.5959P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1045
_refine_ls_wR_factor_ref         0.1070
_reflns_Friedel_coverage         0.945
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     1.000
_reflns_number_gt                14052
_reflns_number_total             14853
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b12984_si_002.cif
_cod_data_source_block           6_mo_BW374_1_0m
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4131918
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.900
_shelx_estimated_absorpt_t_max   0.947
_shelx_res_checksum              49060
_shelx_hkl_checksum              25923