M<sup>3+</sup>(H<sub>2</sub>AsO<sub>4</sub>)(H<sub>2</sub>As<sub>2</sub>O<sub>7</sub>) (M<sup>3+</sup> = Al, Ga) and In<sub>2</sub>(H<sub>2</sub>AsO<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>As<sub>2</sub>O<sub>7</sub>)<sub>2</sub>: a new layer structure type and a new framework structure type containing the rare H<sub>2</sub>As<sub>2</sub>O<sub>7</sub><sup>2-</sup> group.
Schwendtner, Karolina; Kolitsch, Uwe; Acta crystallographica. Section C, Structural chemistry 73 (2017) 600–608; doi:10.1107/S2053229617009676

data_2311886
_publ_section_title
;
 M<sup>3+</sup>(H<sub>2</sub>AsO<sub>4</sub>)(H<sub>2</sub>As<sub>2</sub>O<sub>7</sub>)
 (M<sup>3+</sup> = Al, Ga) and
 In<sub>2</sub>(H<sub>2</sub>AsO<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>As<sub>2</sub>O<sub>7</sub>)<sub>2</sub>:
 a new layer structure type and a new framework structure type containing
 the rare H<sub>2</sub>As<sub>2</sub>O<sub>7</sub><sup>2-</sup> group.
;
_journal_coeditor_code           LY3048
_journal_issue                   'Pt 8'
_journal_name_full
'Acta crystallographica. Section C, Structural chemistry'
_journal_page_first              600
_journal_page_last               608
_journal_paper_doi               10.1107/S2053229617009676
_journal_volume                  73
_journal_year                    2017
_chemical_formula_iupac          'Al (H2 As O4) (H2 As2 O7)'
_chemical_formula_structural     'Al1 (H2 As1 O4) (H2 As2 O7)'
_chemical_formula_sum            'Al As3 H4 O11'
_chemical_formula_weight         431.77
_chemical_name_common
'aluminium dihydrogen arsenate dihydrogen diarsenate'
_chemical_name_systematic
'Aluminium [dihydrogen arsenate(V)] dihydrogen diarsenate(V)'
_space_group_crystal_system      orthorhombic
_space_group_IT_number           62
_space_group_name_Hall           '-P 2ac 2n'
_space_group_name_H-M_alt        'P n m a'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2016/6
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   4.8690(10)
_cell_length_b                   11.071(2)
_cell_length_c                   15.807(3)
_cell_measurement_reflns_used    1830
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      32.577
_cell_measurement_theta_min      2.037
_cell_volume                     852.1(3)
_computing_cell_refinement
;
SCALEPACK (Otwinowski <i>et al.</i>,  2003)
;
_computing_data_collection
;
COLLECT (Nonius, 2003)
;
_computing_data_reduction
;
DENZO and SCALEPACK (Otwinowski <i>et al.</i>,  2003)
;
_computing_molecular_graphics
;
DIAMOND (Brandenburg, 2005)
;
_computing_structure_refinement
;
SHELXL2016 (Sheldrick, 2015)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Nonius KappaCCD single-crystal four-circle'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0217
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            2892
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         32.507
_diffrn_reflns_theta_min         2.577
_exptl_absorpt_coefficient_mu    11.853
_exptl_absorpt_correction_T_max  0.7975
_exptl_absorpt_correction_T_min  0.0442
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SCALEPACK; Otwinowski <i>et al.</i>,  2003)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.366
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       acicular
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.700
_exptl_crystal_size_mid          0.020
_exptl_crystal_size_min          0.020
_refine_diff_density_max         2.014
_refine_diff_density_min         -1.040
_refine_ls_extinction_coef       0.0013(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method
;
SHELXL2016 (Sheldrick, 2015)
;
_refine_ls_goodness_of_fit_ref   1.097
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     85
_refine_ls_number_reflns         1611
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.097
_refine_ls_R_factor_all          0.0410
_refine_ls_R_factor_gt           0.0276
_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^)+(0.0290P)^2^+0.9297P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0587
_refine_ls_wR_factor_ref         0.0623
_reflns_number_gt                1319
_reflns_number_total             1611
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ly3048sup1.cif
_cod_data_source_block           AlH2AsO4H2As2O7
_cod_database_code               2311886
_shelx_estimated_absorpt_t_min   0.044
_shelx_estimated_absorpt_t_max   0.797
_shelx_hkl_checksum              77974
_shelx_res_checksum              77400