data_2640-ICSD
_database_code_ICSD 2640
_audit_creation_date 1980-01-01
_audit_update_record 2016-02-01
_chemical_name_systematic 'Lead diniobium oxide'
_chemical_formula_structural 'Pb Nb2 O6'
_chemical_formula_sum 'Nb2 O6 Pb1'
_exptl_crystal_density_diffrn 6.63
_publ_section_title
;
Nouvelles donnes structurales sur la variete ferroelectrique du metaniobate de
plomb Pb Nb2 O6
;
loop_
_citation_id
_citation_journal_full
_citation_year
_citation_journal_volume
_citation_page_first
_citation_page_last
_citation_journal_id_ASTM
primary
;
Acta Crystallographica, Section B: Structural Crystallography and Crystal
Chemistry
; 1973 29 2204 2210 ACBCAR
loop_
_publ_author_name
'Labbe, P.H.'
'Frey, M.'
'Allais, G.'
_cell_length_a 17.65(2)
_cell_length_b 17.92(2)
_cell_length_c 3.870(5)
_cell_angle_alpha 90.
_cell_angle_beta 90.
_cell_angle_gamma 90.
_cell_volume 1224.03
_cell_formula_units_Z 10
_symmetry_space_group_name_H-M 'C m 2 m'
_symmetry_Int_Tables_number 38
_refine_ls_R_factor_all 0.111
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
1 '-x, y, z'
2 'x, y, -z'
3 '-x, y, -z'
4 'x, y, z'
5 '-x+1/2, y+1/2, z'
6 'x+1/2, y+1/2, -z'
7 '-x+1/2, y+1/2, -z'
8 'x+1/2, y+1/2, z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
Nb5+ 5
Pb2+ 2
O2- -2
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_B_iso_or_equiv
_atom_site_occupancy
_atom_site_attached_hydrogens
Nb1 Nb5+ 2 a 0 0 0 0.88 1. 0
Nb2 Nb5+ 2 a 0 0.5004(17) 0 1.38 1. 0
Nb3 Nb5+ 4 d 0.1807(10) 0.1095(13) 0 1.23 1. 0
Nb4 Nb5+ 4 d 0.318(1) 0.3935(13) 0 1.1 1. 0
Nb5 Nb5+ 4 d 0.3942(12) 0.1802(14) 0 2.18 1. 0
Nb6 Nb5+ 4 d 0.110(1) 0.3198(13) 0 0.8 1. 0
Pb1 Pb2+ 4 e 0.3278(6) 0.0282(11) 0.5 4.01 1. 0
Pb2 Pb2+ 4 e 0.0062(25) 0.1970(12) 0.5 2.67 0.5 0
Pb3 Pb2+ 4 e 0.4832(10) 0.3452(13) 0.5 2.67 0.5 0
Pb4 Pb2+ 4 e 0.2549(11) 0.2504(14) 0.5 1.47 0.5 0
O1 O2- 2 b 0 0 0.5 3. 1. 0
O2 O2- 2 b 0 0.5 0.5 3. 1. 0
O3 O2- 4 e 0.151(9) 0.110(9) 0.5 3. 1. 0
O4 O2- 4 e 0.299(8) 0.395(9) 0.5 3. 1. 0
O5 O2- 4 e 0.402(8) 0.182(8) 0.5 3. 1. 0
O6 O2- 4 e 0.119(8) 0.297(8) 0.5 3. 1. 0
O7 O2- 4 d 0.083(9) 0.092(9) 0 3. 1. 0
O8 O2- 4 d 0.139(9) 0.213(8) 0 3. 1. 0
O9 O2- 4 d 0.221(7) 0.001(9) 0 3. 1. 0
O10 O2- 4 d 0.279(9) 0.135(9) 0 3. 1. 0
O11 O2- 4 d 0.417(9) 0.073(8) 0 3. 1. 0
O12 O2- 4 d 0.081(9) 0.427(8) 0 3. 1. 0
O13 O2- 4 d 0.209(8) 0.334(8) 0 3. 1. 0
O14 O2- 4 d 0.331(8) 0.281(8) 0 3. 1. 0
O15 O2- 4 d 0.433(8) 0.390(9) 0 3. 1. 0
O16 O2- 2 a 0.5 0.235(12) 0 3. 1. 0
O17 O2- 2 a 0 0.252(12) 0 3. 1. 0
#End of TTdata_2640-ICSD
-------------------------
data_185537-ICSD
_database_code_ICSD 185537
_audit_creation_date 2013-02-01
_chemical_name_systematic 'Lead diniobate'
_chemical_formula_structural 'Pb (Nb2 O6)'
_chemical_formula_sum 'Nb2 O6 Pb1'
_exptl_crystal_density_diffrn 6.67
_publ_section_title
;
Structural characterization of orthorhombic and rhombohedral lead meta-niobate
samples
;
loop_
_citation_id
_citation_journal_full
_citation_year
_citation_journal_volume
_citation_page_first
_citation_page_last
_citation_journal_id_ASTM
primary 'Integrated Ferroelectrics' 2010 120 102 113 IFEREU
loop_
_publ_author_name
'Chakraborty, K.R.'
'Sahu, K.R.'
'De, A.'
'De, U.'
_cell_length_a 10.473(2)
_cell_length_b 10.473(2)
_cell_length_c 11.534(2)
_cell_angle_alpha 90.
_cell_angle_beta 90.
_cell_angle_gamma 120.
_cell_volume 1095.6
_cell_formula_units_Z 9
_symmetry_space_group_name_H-M 'R 3 m H'
_symmetry_Int_Tables_number 160
_refine_ls_R_factor_all 0.146
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
1 '-x+y, y, z'
2 'x, x-y, z'
3 '-y, -x, z'
4 '-x+y, -x, z'
5 '-y, x-y, z'
6 'x, y, z'
7 '-x+y+2/3, y+1/3, z+1/3'
8 'x+2/3, x-y+1/3, z+1/3'
9 '-y+2/3, -x+1/3, z+1/3'
10 '-x+y+2/3, -x+1/3, z+1/3'
11 '-y+2/3, x-y+1/3, z+1/3'
12 'x+2/3, y+1/3, z+1/3'
13 '-x+y+1/3, y+2/3, z+2/3'
14 'x+1/3, x-y+2/3, z+2/3'
15 '-y+1/3, -x+2/3, z+2/3'
16 '-x+y+1/3, -x+2/3, z+2/3'
17 '-y+1/3, x-y+2/3, z+2/3'
18 'x+1/3, y+2/3, z+2/3'
loop_
_atom_type_symbol
_atom_type_oxidation_number
Pb2+ 2
Nb5+ 5
O2- -2
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_B_iso_or_equiv
_atom_site_occupancy
_atom_site_attached_hydrogens
Pb1 Pb2+ 3 a 0 0 -0.02(2) 0.5(4) 1. 0
Pb2 Pb2+ 3 a 0 0 0.32(1) 1.6(5) 1. 0
Pb3 Pb2+ 3 a 0 0 0.65(4) 0.9(4) 1. 0
Nb1 Nb5+ 18 c 0.35(3) 0.35(8) 0.16(6) 1.4(5) 1. 0
O1 O2- 18 c 0.37(3) 0.32(5) 0.019(5) 0.5 1. 0
O2 O2- 9 b 0.56(6) 0.44(8) 0.19(4) 0.5 1. 0
O3 O2- 9 b 0.84(8) 0.16(8) 0.19(8) 0.5 1. 0
O4 O2- 18 c 0.43(4) 0.17(4) 0.52(8) 0.5 0.5 0
O5 O2- 9 b 0.15(4) 0.85(4) 0.16(6) 0.5 1. 0
#End of TTdata_185537-ICSD
