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 = -140 C
;
_database_code_amcsd 0019822
_chemical_formula_sum 'Ca B2 O8 H8'
_cell_length_a 7.745
_cell_length_b 5.667
_cell_length_c 8.102
_cell_angle_alpha 113.24
_cell_angle_beta 101.54
_cell_angle_gamma 107.92
_cell_volume 289.121
_exptl_crystal_density_diffrn      2.272
_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   0.23651   0.01813   0.18818   0.00456
B1   0.02870   0.40760   0.23530   0.00659
B2   0.43830   0.31490   0.71190   0.00608
O1   0.06600   0.70800   0.30160   0.00735
O2   0.08300   0.29480   0.06540   0.00684
O3   0.14330   0.37390   0.38590   0.00760
O4   0.18200   0.77240   0.83060   0.00709
O5   0.23840   0.14140   0.68250   0.00773
O6   0.42430   0.73530   0.16060   0.00646
O7   0.46750   0.22880   0.52670   0.00646
O8   0.48580   0.62360   0.80920   0.00671
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 0.00456 0.00443 0.00443 0.00507 0.00190 0.00139
B1 0.00659 0.00722 0.00608 0.00709 0.00291 0.00304
B2 0.00608 0.00621 0.00532 0.00633 0.00215 0.00215
O1 0.00734 0.00887 0.00557 0.00811 0.00329 0.00367
O2 0.00684 0.00671 0.00633 0.00646 0.00215 0.00266
O3 0.00760 0.00773 0.00887 0.00697 0.00405 0.00165
O4 0.00709 0.00646 0.00621 0.00975 0.00279 0.00342
O5 0.00773 0.00608 0.00747 0.00849 0.00165 0.00266
O6 0.00646 0.00671 0.00747 0.00595 0.00355 0.00177
O7 0.00646 0.00747 0.00697 0.00507 0.00329 0.00228
O8 0.00671 0.00659 0.00481 0.00785 0.00241 0.00215