LMucko/crystallography-open-database huggingface dataset:
Magnetic susceptibility of R Co3 B2 (R= Y, Sm, Gd, and Dy)
Ido, H.; Yamada, M.; Nanjo, M.; Journal of Applied Physics 75 (1994) 7140–7142; doi:10.1063/1.356704

data_1510628
_publ_section_title
;
 Magnetic susceptibility of R Co3 B2 (R= Y, Sm, Gd, and Dy)
;
_journal_name_full               'Journal of Applied Physics'
_journal_page_first              7140
_journal_page_last               7142
_journal_paper_doi               10.1063/1.356704
_journal_volume                  75
_journal_year                    1994
_chemical_formula_sum            'B2 Co3 Y'
_chemical_name_systematic        'Co3 Y B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   5.051
_cell_length_b                   5.051
_cell_length_c                   3.035
_cell_volume                     67.057
_citation_journal_id_ASTM        JAPIAU
_cod_data_source_file            boron_109.cif
_cod_data_source_block           B2Co3Y1
_cod_original_formula_sum        'B2 Co3 Y1'
_cod_database_code               1510628
Neue ternaere Boride der Erdalkalimetalle mit Rhodium und Iridium
Jung, W.; Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische Chemie (33,1978-41,1986) 34 (1979) 1221–1228; doi:

data_7209430
_publ_section_title
;
 Neue ternaere Boride der Erdalkalimetalle mit Rhodium und Iridium
;
_journal_name_full
;
Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische
 Chemie (33,1978-41,1986)
;
_journal_page_first              1221
_journal_page_last               1228
_journal_volume                  34
_journal_year                    1979
_chemical_formula_sum            'B2 Ba Rh2'
_chemical_name_systematic        'Ba Rh2 B2'
_space_group_IT_number           139
_symmetry_space_group_name_Hall  '-I 4 2'
_symmetry_space_group_name_H-M   'I 4/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   3.915
_cell_length_b                   3.915
_cell_length_c                   11.25
_cell_volume                     172.431
_citation_journal_id_ASTM        ZNBAD2
_cod_data_source_file            boron_11.cif
_cod_data_source_block           B2Ba1Rh2
_cod_original_cell_volume        172.4313
_cod_original_formula_sum        'B2 Ba1 Rh2'
_cod_database_code               7209430
Crystal structure of Ce Co3 B2 and analogous compounds
Kuz'ma, N.S.; Kripyakevich, P.I.; Bilonizhko, N.S.; Dopovidi Akademii Nauk Ukrains'koi RSR, Seriya A: Fiziko-Tekhnichni ta Matematichni Nauki 1969 (1969) 939–941; doi:

data_1510629
_publ_section_title
;
 Crystal structure of Ce Co3 B2 and analogous compounds
;
_journal_name_full
;
Dopovidi Akademii Nauk Ukrains'koi RSR, Seriya A: Fiziko-Tekhnichni ta
 Matematichni Nauki
;
_journal_page_first              939
_journal_page_last               941
_journal_volume                  1969
_journal_year                    1969
_chemical_formula_sum            'B2 Co3 Y'
_chemical_name_systematic        'Y Co3 B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   5.033
_cell_length_b                   5.033
_cell_length_c                   3.038
_cell_volume                     66.646
_citation_journal_id_ASTM        DUKABM
_cod_data_source_file            boron_110.cif
_cod_data_source_block           B2Co3Y1
_cod_original_cell_volume        66.64572
_cod_original_formula_sum        'B2 Co3 Y1'
_cod_database_code               1510629
Ueber SE-Metall-Kobaltboride
Rogl, P.; Monatshefte fuer Chemie (-108,1977) 104 (1973) 1623–1631; doi:

data_1510630
_publ_section_title
;
 Ueber SE-Metall-Kobaltboride
;
_journal_name_full               'Monatshefte fuer Chemie (-108,1977)'
_journal_page_first              1623
_journal_page_last               1631
_journal_volume                  104
_journal_year                    1973
_chemical_formula_sum            'B2 Co3 Yb'
_chemical_name_systematic        'Co3 Yb B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   4.985
_cell_length_b                   4.985
_cell_length_c                   3.02
_cell_volume                     64.993
_citation_journal_id_ASTM        MOCHAP
_cod_data_source_file            boron_111.cif
_cod_data_source_block           B2Co3Yb1
_cod_original_cell_volume        64.9932
_cod_original_formula_sum        'B2 Co3 Yb1'
_cod_database_code               1510630
Crystal structures of Zr Co3 B2 and Hf Co3 B2
Kuz'ma, Yu.B.; Kripyakevich, P.I.; Voroshilov, Yu.V.; Kristallografiya 15 (1970) 934–938; doi:

data_1510631
_publ_section_title
;
 Crystal structures of Zr Co3 B2 and Hf Co3 B2
;
_journal_name_full               Kristallografiya
_journal_page_first              934
_journal_page_last               938
_journal_volume                  15
_journal_year                    1970
_chemical_formula_sum            'B2 Co3 Zr'
_chemical_name_systematic        'Zr Co3 B2'
_space_group_IT_number           148
_symmetry_space_group_name_Hall  '-R 3'
_symmetry_space_group_name_H-M   'R -3 :H'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            9
_cell_length_a                   8.418
_cell_length_b                   8.418
_cell_length_c                   9.132
_cell_volume                     560.421
_citation_journal_id_ASTM        KRISAJ
_cod_data_source_file            boron_112.cif
_cod_data_source_block           B2Co3Zr1
_cod_original_formula_sum        'B2 Co3 Zr1'
_cod_database_code               1510631
Kobaltreiche ternaere Phasen in den Dreistoffsystemen Kobalt-Hafnium-Bor und Kobalt-Zirkon-Bor
Schoebel, J.D.; Stadelmaier, H.H.; Metall (Berlin) 23 (1969) 25–27; doi:

data_1510632
_publ_section_title
;
 Kobaltreiche ternaere Phasen in den Dreistoffsystemen Kobalt-Hafnium-Bor
 und Kobalt-Zirkon-Bor
;
_journal_name_full               'Metall (Berlin)'
_journal_page_first              25
_journal_page_last               27
_journal_volume                  23
_journal_year                    1969
_chemical_formula_sum            'B2 Co3 Zr'
_chemical_name_systematic        'Co3 Zr B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   4.863
_cell_length_b                   4.863
_cell_length_c                   3.043
_cell_volume                     62.322
_citation_journal_id_ASTM        MTLLAF
_cod_data_source_file            boron_113.cif
_cod_data_source_block           B2Co3Zr1
_cod_original_cell_volume        62.32196
_cod_original_formula_sum        'B2 Co3 Zr1'
_cod_database_code               1510632
Synthese und roentgenographische Charakterisierung von zwei neuen Verbindungen des Ludwigit-Strukturtyps: Co5 Sn (B O3)2 O4 und Co5 Mn (B O3)2 O4
Bluhm, K.; Utzolino, A.; Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische Chemie (42,1987-) 51 (1996) 305–308; doi:

data_7209431
_publ_section_title
;
 Synthese und roentgenographische Charakterisierung von zwei neuen
 Verbindungen des Ludwigit-Strukturtyps: Co5 Sn (B O3)2 O4 und Co5 Mn (B
 O3)2 O4
;
_journal_name_full
;
Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische
 Chemie (42,1987-)
;
_journal_page_first              305
_journal_page_last               308
_journal_volume                  51
_journal_year                    1996
_chemical_formula_sum            'B2 Co5 Mn O10'
_chemical_name_systematic        'Co5 Mn (B O3)2 O4'
_space_group_IT_number           55
_symmetry_space_group_name_Hall  '-P 2 2ab'
_symmetry_space_group_name_H-M   'P b a m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   9.2507
_cell_length_b                   12.4167
_cell_length_c                   3.0524
_cell_volume                     350.608
_citation_journal_id_ASTM        ZNBSEN
_cod_data_source_file            boron_114.cif
_cod_data_source_block           B2Co5Mn1O10
_cod_original_cell_volume        350.6084
_cod_original_formula_sum        'B2 Co5 Mn1 O10'
_cod_database_code               7209431
Synthese und roengenographische Charakterisierung von zwei neuen Verbindungen des Ludwigit-Strukturtyps: Co5 Sn (B O3)2 O4 und Co5 Mn (B O3)2 O4
Bluhm, K.; Utzolino, A.; Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische Chemie (42,1987-) 51 (1996) 305–308; doi:

data_7209432
_publ_section_title
;
 Synthese und roengenographische Charakterisierung von zwei neuen
 Verbindungen des Ludwigit-Strukturtyps: Co5 Sn (B O3)2 O4 und Co5 Mn (B
 O3)2 O4
;
_journal_name_full
;
Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische
 Chemie (42,1987-)
;
_journal_page_first              305
_journal_page_last               308
_journal_volume                  51
_journal_year                    1996
_chemical_formula_sum            'B2 Co5 O10 Sn'
_chemical_name_systematic        'Co5 Sn (B O3)2 O4'
_space_group_IT_number           55
_symmetry_space_group_name_Hall  '-P 2 2ab'
_symmetry_space_group_name_H-M   'P b a m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   9.444
_cell_length_b                   12.338
_cell_length_c                   3.1054
_cell_volume                     361.841
_citation_journal_id_ASTM        ZNBSEN
_cod_data_source_file            boron_115.cif
_cod_data_source_block           B2Co5O10Sn1
_cod_original_cell_volume        361.8415
_cod_original_formula_sum        'B2 Co5 O10 Sn1'
_cod_database_code               7209432
The crystal structure of Ti3 Co5 B2
Yarmolyuk, Ya.P.; Kuz'ma, Yu.B.; Zhurnal Strukturnoi Khimii (Issue-No. from 1981) 12 (1971) 458–461; doi:

data_1510633
_publ_section_title
;
 The crystal structure of Ti3 Co5 B2
;
_journal_name_full
'Zhurnal Strukturnoi Khimii (Issue-No. from 1981)'
_journal_page_first              458
_journal_page_last               461
_journal_volume                  12
_journal_year                    1971
_chemical_formula_sum            'B2 Co5 Ti3'
_chemical_name_systematic        'Ti3 Co5 B2'
_space_group_IT_number           127
_symmetry_space_group_name_Hall  '-P 4 2ab'
_symmetry_space_group_name_H-M   'P 4/m b m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   8.489
_cell_length_b                   8.489
_cell_length_c                   3.038
_cell_volume                     218.928
_citation_journal_id_ASTM        ZSTKAI
_cod_data_source_file            boron_116.cif
_cod_data_source_block           B2Co5Ti3
_cod_original_cell_volume        218.9278
_cod_database_code               1510633
Crystal structure of uranium cobalt boride U3 Co7 B2
Volovka, I.P.; Kuz'ma, Yu.B.; Izvestiya Akademii Nauk SSSR, Neorganicheskie Materialy 16 (1980) 1681–1683; doi:

data_1510634
_publ_section_title
;
 Crystal structure of uranium cobalt boride U3 Co7 B2
;
_journal_name_full
'Izvestiya Akademii Nauk SSSR, Neorganicheskie Materialy'
_journal_page_first              1681
_journal_page_last               1683
_journal_volume                  16
_journal_year                    1980
_chemical_formula_sum            'B2 Co7 U3'
_chemical_name_systematic        'U3 Co7 B2'
_space_group_IT_number           194
_symmetry_space_group_name_Hall  '-P 6c 2c'
_symmetry_space_group_name_H-M   'P 63/m m c'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            2
_cell_length_a                   4.98
_cell_length_b                   4.98
_cell_length_c                   13.947
_cell_volume                     299.551
_citation_journal_id_ASTM        IVNMAW
_cod_data_source_file            boron_117.cif
_cod_data_source_block           B2Co7U3
_cod_original_cell_volume        299.5505
_cod_database_code               1510634
Transition metal diborides
Post, B.; Moskowitz, D.; Glaser, F.W.; Acta Metallurgica 2 (1954) 20–25; doi:10.1016/0001-6160(54)90090-5

data_1510635
_publ_section_title
;
 Transition metal diborides
;
_journal_name_full               'Acta Metallurgica'
_journal_page_first              20
_journal_page_last               25
_journal_paper_doi               10.1016/0001-6160(54)90090-5
_journal_volume                  2
_journal_year                    1954
_chemical_formula_sum            'B2 Cr0.5 Mo0.5'
_chemical_name_systematic        '(Cr Mo B4)0.5'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   3.01
_cell_length_b                   3.01
_cell_length_c                   3.12
_cell_volume                     24.480
_citation_journal_id_ASTM        AMETAR
_cod_data_source_file            boron_118.cif
_cod_data_source_block           B2Cr0.5Mo0.5
_cod_original_cell_volume        24.48038
_cod_database_code               1510635
Transition metal diborides
Post, B.; Glaser, F.W.; Moskowitz, D.; Acta Metallurgica 2 (1954) 20–25; doi:10.1016/0001-6160(54)90090-5

data_1510636
_publ_section_title
;
 Transition metal diborides
;
_journal_name_full               'Acta Metallurgica'
_journal_page_first              20
_journal_page_last               25
_journal_paper_doi               10.1016/0001-6160(54)90090-5
_journal_volume                  2
_journal_year                    1954
_chemical_formula_sum            'B2 Cr0.5 Ta0.5'
_chemical_name_systematic        '(Cr0.5 Ta0.5) B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   3.025
_cell_length_b                   3.025
_cell_length_c                   3.21
_cell_volume                     25.438
_citation_journal_id_ASTM        AMETAR
_cod_data_source_file            boron_119.cif
_cod_data_source_block           B2Cr0.5Ta0.5
_cod_original_cell_volume        25.4382
_cod_database_code               1510636
Ba B2 S4 : das erste nicht-oxidische Chalkogenoborat mit trigonal-planar und tetraedrisch koordiniertem Bor
Wulff, M.; Krebs, B.; Hammerschmidt, A.; Doech, M.; Zeitschrift fuer Anorganische und Allgemeine Chemie 628 (2002) 2637–2640; doi:10.1002/1521-3749(200212)628:12<2637::AID-ZAAC2637>3.0.CO;2-0

data_1510637
_publ_section_title
;
 Ba B2 S4 : das erste nicht-oxidische Chalkogenoborat mit trigonal-planar
 und tetraedrisch koordiniertem Bor
;
_journal_name_full
'Zeitschrift fuer Anorganische und Allgemeine Chemie'
_journal_page_first              2637
_journal_page_last               2640
_journal_paper_doi
10.1002/1521-3749(200212)628:12<2637::AID-ZAAC2637>3.0.CO;2-0
_journal_volume                  628
_journal_year                    2002
_chemical_formula_sum            'B2 Ba S4'
_chemical_name_systematic        'Ba (B2 S4)'
_space_group_IT_number           9
_symmetry_space_group_name_Hall  'C -2yc'
_symmetry_space_group_name_H-M   'C 1 c 1'
_cell_angle_alpha                90
_cell_angle_beta                 110.961
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.6465
_cell_length_b                   15.6995
_cell_length_c                   6.0306
_cell_volume                     587.631
_citation_journal_id_ASTM        ZAACAB
_cod_data_source_file            boron_12.cif
_cod_data_source_block           B2Ba1S4
_cod_original_cell_volume        587.6307
_cod_original_formula_sum        'B2 Ba1 S4'
_cod_database_code               1510637
Transition metal diborides
Glaser, F.W.; Post, B.; Moskowitz, D.; Acta Metallurgica 2 (1954) 20–25; doi:10.1016/0001-6160(54)90090-5

data_1510638
_publ_section_title
;
 Transition metal diborides
;
_journal_name_full               'Acta Metallurgica'
_journal_page_first              20
_journal_page_last               25
_journal_paper_doi               10.1016/0001-6160(54)90090-5
_journal_volume                  2
_journal_year                    1954
_chemical_formula_sum            'B2 Cr0.5 Ti0.5'
_chemical_name_systematic        '(Cr0.5 Ti0.5) B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   2.99
_cell_length_b                   2.99
_cell_length_c                   3.14
_cell_volume                     24.311
_citation_journal_id_ASTM        AMETAR
_cod_data_source_file            boron_120.cif
_cod_data_source_block           B2Cr0.5Ti0.5
_cod_original_cell_volume        24.31099
_cod_database_code               1510638
Transition metal diborides
Moskowitz, D.; Glaser, F.W.; Post, B.; Acta Metallurgica 2 (1954) 20–25; doi:10.1016/0001-6160(54)90090-5

data_1510639
_publ_section_title
;
 Transition metal diborides
;
_journal_name_full               'Acta Metallurgica'
_journal_page_first              20
_journal_page_last               25
_journal_paper_doi               10.1016/0001-6160(54)90090-5
_journal_volume                  2
_journal_year                    1954
_chemical_formula_sum            'B2 Cr0.5 V0.5'
_chemical_name_systematic        '(Cr0.5 V0.5) B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   2.99
_cell_length_b                   2.99
_cell_length_c                   3.045
_cell_volume                     23.575
_citation_journal_id_ASTM        AMETAR
_cod_data_source_file            boron_121.cif
_cod_data_source_block           B2Cr0.5V0.5
_cod_original_cell_volume        23.57547
_cod_database_code               1510639
Magneto-volume effect of the interant-electron antiferromatgnet Cr B2
Nishihara, Y.; Yamaguchi, Y.; Tokumoto, M.; Ogawa, S.; Poroshkovaya Metallurgiya 8 (1969) 403–410; doi:

data_1510640
_publ_section_title
;
 Magneto-volume effect of the interant-electron antiferromatgnet Cr B2
;
_journal_name_full               'Poroshkovaya Metallurgiya'
_journal_page_first              403
_journal_page_last               410
_journal_volume                  8
_journal_year                    1969
_chemical_formula_sum            'B2 Cr0.6 Mo0.4'
_chemical_name_systematic        '(Cr0.6 Mo0.4) B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   3.069
_cell_length_b                   3.069
_cell_length_c                   3.112
_cell_volume                     25.384
_citation_journal_id_ASTM        PMANAI
_cod_data_source_file            boron_122.cif
_cod_data_source_block           B2Cr0.6Mo0.4
_cod_original_cell_volume        25.38423
_cod_database_code               1510640
The crystal structure of an M3 B2 double boride
Beattie, H.J.jr.; Acta Crystallographica (1,1948-23,1967) 11 (1958) 607–609; doi:10.1107/S0365110X58001626

data_2310086
_publ_section_title
;
 The crystal structure of an M3 B2 double boride
;
_journal_name_full               'Acta Crystallographica (1,1948-23,1967)'
_journal_page_first              607
_journal_page_last               609
_journal_paper_doi               10.1107/S0365110X58001626
_journal_volume                  11
_journal_year                    1958
_chemical_formula_sum            'B2 Cr0.64 Fe0.43 Mo1.08 Ni0.21 Ti0.64'
_chemical_name_systematic        'Cr0.64 Fe0.43 Mo1.08 Ni0.21 Ti0.64 B2'
_space_group_IT_number           127
_symmetry_space_group_name_Hall  '-P 4 2ab'
_symmetry_space_group_name_H-M   'P 4/m b m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   5.783
_cell_length_b                   5.783
_cell_length_c                   3.134
_cell_volume                     104.811
_citation_journal_id_ASTM        ACCRA9
_cod_data_source_file            boron_123.cif
_cod_data_source_block           B2Cr0.64Fe0.43Mo1.08Ni0.21Ti0.64
_cod_original_cell_volume        104.8106
_cod_database_code               2310086
Transition metal diborides
Moskowitz, D.; Glaser, F.W.; Post, B.; Acta Metallurgica 2 (1954) 20–25; doi:10.1016/0001-6160(54)90090-5

data_1510641
_publ_section_title
;
 Transition metal diborides
;
_journal_name_full               'Acta Metallurgica'
_journal_page_first              20
_journal_page_last               25
_journal_paper_doi               10.1016/0001-6160(54)90090-5
_journal_volume                  2
_journal_year                    1954
_chemical_formula_sum            'B2 Cr'
_chemical_name_systematic        'Cr B2'
_space_group_IT_number           191
_symmetry_space_group_name_Hall  '-P 6 2'
_symmetry_space_group_name_H-M   'P 6/m m m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   2.97
_cell_length_b                   2.97
_cell_length_c                   3.07
_cell_volume                     23.452
_citation_journal_id_ASTM        AMETAR
_cod_data_source_file            boron_124.cif
_cod_data_source_block           B2Cr1
_cod_original_cell_volume        23.45211
_cod_original_formula_sum        'B2 Cr1'
_cod_database_code               1510641