data_global
_chemical_name_mineral 'Frolovite'
loop_
_publ_author_name
'Simonov M A'
'Kazanskaya E V'
'Egorov-Tismenko Y K'
'Zhelezi E P'
'Belov N V'
_journal_name_full 'Doklady Akademii Nauk SSSR'
_journal_volume 230 
_journal_year 1976
_journal_page_first 91
_journal_page_last 94
_publ_section_title
;
 Refinement of the crystal-structure of frolovite, Ca[B(OH)4]2
 Note: T = 18 C
;
_database_code_amcsd 0019821
_chemical_formula_sum 'Ca B2 O8 H8'
_cell_length_a 7.774
_cell_length_b 5.680
_cell_length_c 8.136
_cell_angle_alpha 113.15
_cell_angle_beta 101.67
_cell_angle_gamma 107.87
_cell_volume 292.206
_exptl_crystal_density_diffrn      2.248
_symmetry_space_group_name_H-M 'P -1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Ca   0.23679   0.01781   0.18910   0.00925
B1   0.02780   0.40720   0.23490   0.01064
B2   0.43880   0.31510   0.71200   0.00963
O1   0.06550   0.70600   0.30140   0.01254
O2   0.08300   0.29480   0.06540   0.01267
O3   0.14180   0.37110   0.38410   0.01393
O4   0.18190   0.77280   0.83150   0.01267
O5   0.23920   0.14360   0.68280   0.01406
O6   0.42450   0.73490   0.16120   0.01140
O7   0.46720   0.22910   0.52740   0.01153
O8   0.48620   0.62270   0.80830   0.01165
H1   0.02000   0.29200   0.68800   0.12792
H2   0.19100   0.41600   0.07800   0.03673
H3   0.23200   0.48500   0.41500   0.15198
H4   0.79300   0.10700   0.20200   0.04433
H5   0.18300   0.02700   0.58100   0.03800
H6   0.54100   0.27700   0.92900   0.03800
H7   0.49800   0.15000   0.52000   0.16465
H8   0.60900   0.34600   0.20400   0.03420
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Ca 0.00912 0.00874 0.01026 0.00393 0.00279 0.00494
B1 0.01051 0.01013 0.01115 0.00443 0.00355 0.00545
B2 0.00975 0.00963 0.00963 0.00431 0.00355 0.00443
O1 0.01406 0.00849 0.01469 0.00456 0.00507 0.00481
O2 0.01304 0.01102 0.01178 0.00393 0.00507 0.00405
O3 0.01583 0.01773 0.01330 0.00899 0.00342 0.00887
O4 0.00950 0.01191 0.01798 0.00380 0.00507 0.00849
O5 0.01000 0.01292 0.01735 0.00279 0.00545 0.00697
O6 0.01216 0.01330 0.01140 0.00709 0.00367 0.00722
O7 0.01380 0.01191 0.00912 0.00583 0.00431 0.00481
O8 0.01165 0.00785 0.01406 0.00405 0.00418 0.00380