The low-temperature crystal structure of the multiferroic melilite Ca~2~CoSi~2~O~7~
Sazonov, Andrew; Hutanu, Vladimir; Meven, Martin; Roth, Georg; Kézsmárki, István; Murakawa, Hiroshi; Tokura, Yoshinori; Náfrádi, Bálint; Acta Crystallographica Section B 72 (2016) 126–132; doi:10.1107/S2052520615023057

data_2107468
_publ_section_title
;
 The low-temperature crystal structure of the multiferroic melilite
 Ca~2~CoSi~2~O~7~
;
_journal_coeditor_code           BP5083
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              126
_journal_page_last               132
_journal_paper_doi               10.1107/S2052520615023057
_journal_volume                  72
_journal_year                    2016
_chemical_formula_sum            'Ca2 Co O7 Si2'
_chemical_formula_weight         307.26
_space_group_IT_number           18
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2 2ab'
_symmetry_space_group_name_H-M   'P 21 21 2'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            18
_cell_length_a                   23.520(10)
_cell_length_b                   23.520(10)
_cell_length_c                   5.030(10)
_cell_measurement_temperature    10
_cell_volume                     2783(6)
_diffrn_ambient_temperature      10
_diffrn_measured_fraction_theta_full 0.62
_diffrn_measured_fraction_theta_max 0.28
_diffrn_measurement_device_type  'Four-circle diffractometer'
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     1.1695
_diffrn_reflns_av_R_equivalents  0.0185
_diffrn_reflns_limit_h_max       36
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       36
_diffrn_reflns_limit_k_min       -30
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            3127
_diffrn_reflns_theta_full        20.26
_diffrn_reflns_theta_max         64.92
_diffrn_reflns_theta_min         4.03
_exptl_absorpt_coefficient_mu    0.016
_exptl_crystal_colour            Blue
_exptl_crystal_density_diffrn    3.3035
_exptl_crystal_description       Cylinder
_exptl_crystal_F_000             2718
_exptl_crystal_size_max          4
_exptl_crystal_size_rad          2
_refine_ls_extinction_coef       36E1(3)
_refine_ls_extinction_method
'B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)'
_refine_ls_goodness_of_fit_ref   3.17
_refine_ls_number_constraints    51
_refine_ls_number_parameters     168
_refine_ls_number_reflns         1883
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0428
_refine_ls_R_factor_gt           0.0428
_refine_ls_shift/su_max          0.0004
_refine_ls_shift/su_mean         0.0001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     w=1/(\s^2^(I)+0.0004I^2^)
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_gt          0.0988
_refine_ls_wR_factor_ref         0.0988
_reflns_number_gt                1883
_reflns_number_total             2006
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            bp5083sup1.cif
_cod_data_source_block           I
_cod_depositor_comments
;Adding full bibliography for 2107468.cif.

 Adding full bibliography for 2107468.cif.
;
_cod_original_cell_volume        2782.5
_cod_original_formula_sum        'Ca2 Co1 O7 Si2'
_cod_database_code               2107468
_cod_database_fobs_code          2107468