Finding the First Squarates Nonlinear Optical Crystal NaHC4O4·H2O with Strong Second Harmonic Generation and Giant Birefringence
Zhang, Xiaodong; Cao, Dongxu; Yang, Daqing; Wang, Ying; Wu, Kui; Lee, Ming-Hsien; Zhang, Bingbing; ACS Materials Letters  (2022) 572–576; doi:10.1021/acsmaterialslett.2c00114

data_4519425
_publ_section_title
;
 Finding the First Squarates Nonlinear Optical Crystal NaHC4O4&#x00B7;H2O
 with Strong Second Harmonic Generation and Giant Birefringence
;
_journal_name_full               'ACS Materials Letters'
_journal_page_first              572
_journal_page_last               576
_journal_paper_doi               10.1021/acsmaterialslett.2c00114
_journal_year                    2022
_chemical_formula_sum            'C4 H3 Na O5'
_chemical_formula_weight         154.05
_space_group_crystal_system      monoclinic
_space_group_IT_number           7
_space_group_name_Hall           'P -2yc'
_space_group_name_H-M_alt        'P 1 c 1'
_atom_sites_solution_hydrogens   difmap
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                90
_cell_angle_beta                 97.981(6)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   3.6294(6)
_cell_length_b                   8.1444(13)
_cell_length_c                   9.4044(16)
_cell_measurement_temperature    273(2)
_cell_volume                     275.29(8)
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      273(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.995
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0215
_diffrn_reflns_av_unetI/netI     0.0127
_diffrn_reflns_Laue_measured_fraction_full 0.994
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            8945
_diffrn_reflns_point_group_measured_fraction_full 0.995
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.453
_diffrn_reflns_theta_min         2.501
_exptl_absorpt_coefficient_mu    0.237
_exptl_crystal_density_diffrn    1.858
_exptl_crystal_F_000             156
_refine_diff_density_max         0.280
_refine_diff_density_min         -0.160
_refine_diff_density_rms         0.035
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   0.2(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.060
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     101
_refine_ls_number_reflns         1263
_refine_ls_number_restraints     5
_refine_ls_restrained_S_all      1.059
_refine_ls_R_factor_all          0.0216
_refine_ls_R_factor_gt           0.0209
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0358P)^2^+0.0221P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0550
_refine_ls_wR_factor_ref         0.0557
_reflns_Friedel_coverage         0.986
_reflns_Friedel_fraction_full    0.996
_reflns_Friedel_fraction_max     0.997
_reflns_number_gt                1226
_reflns_number_total             1263
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            tz2c00114_si_002.cif
_cod_data_source_block           1
_cod_original_sg_symbol_H-M      'P c'
_cod_database_code               4519425
_shelx_shelxl_version_number     2018/3
_shelx_res_checksum              42841
_shelx_hkl_checksum              44021