Structural relationship of various squarates
Lee, Chi-Rung; Wang, Chih-Chieh; Wang, Yu; Acta Crystallographica Section B 52 (1996) 966–975; doi:10.1107/S0108768196009639

data_2101641
_publ_section_title
;
 Structural relationship of various squarates
;
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              966
_journal_page_last               975
_journal_paper_doi               10.1107/S0108768196009639
_journal_volume                  52
_journal_year                    1996
_chemical_formula_moiety         '[Ni (C4 O4 )(H2 O)4 ]'
_chemical_formula_sum            'C4 H8 Ni O8'
_chemical_formula_weight         242.81
_chemical_name_systematic        ?
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_cell_angle_alpha                90.0
_cell_angle_beta                 99.43(2)
_cell_angle_gamma                90.0
_cell_formula_units_Z            4
_cell_length_a                   8.9315(16)
_cell_length_b                   13.246(3)
_cell_length_c                   6.6893(18)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    298
_cell_measurement_theta_max      18.81
_cell_measurement_theta_min      11.39
_cell_volume                     780.7(3)
_computing_data_reduction
' NRCVAX DATRD2 (Gabe, Le Page, Charland, Lee & White, 1989)'
_computing_molecular_graphics
' NRCVAX (Gabe, Le Page, Charland, Lee & White, 1989)'
_computing_publication_material
' NRCVAX TABLES (Gabe, Le Page, Charland, Lee & White, 1989)'
_computing_structure_refinement
' NRCVAX LSTSQ (Gabe, Le Page, Charland, Lee & White, 1989)'
_computing_structure_solution
' NRCVAX SOLVER (Gabe, Le Page, Charland, Lee & White, 1989)'
_diffrn_ambient_temperature      298
_diffrn_measurement_device       'Nonius CAD-4    '
_diffrn_measurement_method       '\q/2\q b/P/b '
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'xray tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.000
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            693
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         0.00
_diffrn_standards_decay_%        0.0
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    2.51
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.955
_exptl_absorpt_correction_type   '\y scan (north, Phillips & Mathews, 1968)'
_exptl_crystal_colour            'pale green'
_exptl_crystal_density_diffrn    2.066
_exptl_crystal_description       rectangle
_exptl_crystal_F_000             496
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.38
_refine_diff_density_min         -0.47
_refine_ls_extinction_coef       4.2195(3421)x10^4^
_refine_ls_extinction_method     'Secondary (Larson, 1970)'
_refine_ls_goodness_of_fit_obs   2.58
_refine_ls_hydrogen_treatment    'H atoms placed in calculated positions'
_refine_ls_matrix_type           atomblock
_refine_ls_number_parameters     66
_refine_ls_number_reflns         574
_refine_ls_R_factor_all          0.034
_refine_ls_R_factor_obs          0.026
_refine_ls_shift/esd_max         0.002
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 1/\s^2^(F)'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.025
_refine_ls_wR_factor_obs         0.025
_reflns_number_observed          574
_reflns_number_total             693
_reflns_observed_criterion       'Inet > 2.0\s(Inet)'
_cod_data_source_file            oa0002.cif
_cod_data_source_block           2
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value '1/\s^2^(F)' was changed to
'calc'. New tag '_refine_ls_weighting_details' was created. The value
of the new tag was set to 'w = 1/\s^2^(F)'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2101641