#------------------------------------------------------------------------------
#$Date: 2008-01-13 22:15:36 +0000 (Sun, 13 Jan 2008) $
#$Revision: 14 $
#$URL: svn://www.crystallography.net/cod/cif/8/8101619.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_8101619
_journal_name_full  'Zeitschrift fur Kristallographie - NCS'
_journal_year       1999
_publ_section_title
;
Structure of the New Nonlinear Optical Crystal K2Al2B2O7
;
loop_
_publ_author_name
  'Hu, Zhang-Gui '
  'Higashiyama, T.'
  ' Yoshimura, M.'
  'Mori, Y.'
  'Sasaki, T.'
  'Hu, Zhang-Gui'
_chemical_formula_moiety  ' K2Al2B2O7 '
_chemical_formula_structural  ' K2 Al2 B2 O7 '
_chemical_formula_sum  'Al2 B2 K2 O7'
_chemical_formula_iupac  ' K2Al2B2O7 '
_chemical_formula_weight  265.78
_symmetry_cell_setting  trigonal
_symmetry_space_group_name_H-M  'P 3 2 1'
loop_
_symmetry_equiv_pos_as_xyz
' X, Y,  Z '
' -Y, X-Y, Z '
' -X+Y, -X, Z '
' Y, X, -Z '
' -X, -X+Y, -Z '
' X-Y, -Y, -Z '
_cell_length_a  8.5657(9)
_cell_length_b  8.5657(9)
_cell_length_c  8.463(2)
_cell_angle_alpha  90.0
_cell_angle_beta  90.0
_cell_angle_gamma  120.0
_cell_volume  537.7(1)
_cell_formula_units_z  3
_cell_measurement_temperature  297
_exptl_crystal_ density_diffrn  2.462
_reflns_ls_R_factor_gt  0.018
_reflns_ls_R_factor_obs  0.018
_refine_ls_wR_factor_obs  0.060
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_B_iso_or_eqiv
_atom_site_thermal_displace_type
_atom_site_occupancy
K1  0.30912(4)  0.0000  0.0000  1.499(5)  Uani  1
K2  0.35847(4)  0.0000  0.5000  1.473(5)  Uani  1
Al1  0.0000  0.0000  0.29918(5)  0.779(7)  Uani  1
Al2  0.3333  0.6667  0.18278(6)  0.702(6)  Uani  1
Al3  0.6667  0.3333  0.22152(6)  0.747(6)  Uani  1
O1  0.15703(9)  0.21362(9)  0.2261(1)  1.45(1)  Uani  1
O2  0.39833(9)  0.51554(8)  0.2524(1)  1.40(1)  Uani  1
O3  0.45151(9)  0.2732(1)  0.2934(1)  1.29(1)  Uani  1
O4  0.0000  0.0000  0.5000  2.62(4)  Uani  1
O5  0.6667  0.3333  0.0196(2)  2.29(3)  Uani  1
B1  0.3350(1)  0.3339(1)  0.2569(1)  0.830(9)  Uani  1
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_23
_atom_site_aniso_U_13
K1  .01842(7)  .0183(1)  .0202(1)  .00916(5)  .00259(6)  .0052(1)
K2  .01858(7)  .0203(1)  .0177(1)  .01014(6)  .00305(6)  .0061(1)
Al1  .00846(9)  .00846(9) .0127(2)  .00423(5)  .0000  .0000
Al2  .0075(1)  .0075(1)  .0117(2)  .00375(6)  .0000  .0000
Al3  .0084(1)  .0084(1)  .0115(2)  .00423(6)  .0000  .0000
O1  .0087(2)  .0102(3)  .0325(4)  .0018(2)  -.0046(3)  .0040(3)
O2  .0130(2)  .0078(2)  .0331(4)  .0056(2)  -.0045(3)  .0007(2)
O3  .0092(2)  .0128(2)  .0286(4)  .0068(2)  .0031(2)  .0071(2)
O4  .0441(8)  .0441(8)  .0113(7)  .0220(4)  .0000  .0000
O5  .0376(5)  .0376(5)  .0117(4)  .0188(3)  .0000  .0000
B1  .0078(4)  .0080(4)  .0154(4)  .0037(2)  .0008(2)  .0018(3)
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_publf_lag
  Al1  O1  1.7546(7)  no
  Al2  O2  1.7475(9)  no
  Al3  O3  1.7557(8)  no
  Al1  O4  1.6995(4)  no
  Al2  O5  1.712(2)  no
  O1  B1  1.372(1)  no
  O2  B1  1.368(1)  no
  O3  B1  1.371(2)  no