_space_group.reference_setting

Name:
'_space_group.reference_setting'

Definition:

   The reference setting of a given space group is the setting
   chosen by the International Union of Crystallography as a
   unique setting to which other settings can be referred
   using the transformation matrix column pair given in
   _space_group.transform_Pp_abc and _space_group.transform_Qq_xyz.

   The settings are given in the enumeration list in the form
   '_space_group.IT_number:_space_group.name_Hall'. The
   space-group number defines the space-group type and the
   Hall symbol specifies the symmetry generators referred to
   the reference coordinate system.

   The 230 reference settings chosen are identical to the settings
   listed in International Tables for Crystallography Volume A
   (2002). For the space groups where more than one setting is
   given in International Tables, the following choices have
   been made.

   For monoclinic space groups: unique axis b and cell choice 1.

   For space groups with two origins: origin choice 2 (origin at
   inversion centre, indicated by adding :2 to the Hermann-Mauguin
   symbol in the enumeration list).

   For rhombohedral space groups: hexagonal axes (indicated by
   adding :h to the Hermann-Mauguin symbol in the enumeration list).

   Based on the symmetry table of R. W. Grosse-Kunstleve, ETH,
   Zurich.

   The enumeration list may be extracted from the dictionary
   and stored as a separate CIF that can be referred to as
   required.

   In the enumeration list, each reference setting is identified
   by Schoenflies symbol and by the Hermann-Mauguin symbol,
   augmented by :2 or :h suffixes as described above.

   Ref: International Tables for Crystallography (2002). Volume A,
        Space-group symmetry, edited by Th. Hahn, 5th ed.
        Dordrecht: Kluwer Academic Publishers.

        Grosse-Kunstleve, R. W. (2001). Xtal System of
        Crystallographic Programs, System Documentation.
        http://xtal.crystal.uwa.edu.au/man/xtal3.7-228.html
        (or follow links to Docs->Space-Group Symbols from
        http://xtal.sourceforge.net).

Type: char

Mandatory item: no

The data value must be one of the following:

'001:P 1' C1.1 P 1

'002:-P 1' Ci.1 P -1

'003:P 2y' C2.1 P 1 2 1

'004:P 2yb' C2.2 P 1 21 1

'005:C 2y' C2.3 C 1 2 1

'006:P -2y' Cs.1 P 1 m 1

'007:P -2yc' Cs.2 P 1 c 1

'008:C -2y' Cs.3 C 1 m 1

'009:C -2yc' Cs.4 C 1 c 1

'010:-P 2y' C2h.1 P 1 2/m 1

'011:-P 2yb' C2h.2 P 1 21/m 1

'012:-C 2y' C2h.3 C 1 2/m 1

'013:-P 2yc' C2h.4 P 1 2/c 1

'014:-P 2ybc' C2h.5 P 1 21/c 1

'015:-C 2yc' C2h.6 C 1 2/c 1

'016:P 2 2' D2.1 P 2 2 2

'017:P 2c 2' D2.2 P 2 2 21

'018:P 2 2ab' D2.3 P 21 21 2

'019:P 2ac 2ab' D2.4 P 21 21 21

'020:C 2c 2' D2.5 C 2 2 21

'021:C 2 2' D2.6 C 2 2 2

'022:F 2 2' D2.7 F 2 2 2

'023:I 2 2' D2.8 I 2 2 2

'024:I 2b 2c' D2.9 I 21 21 21

'025:P 2 -2' C2v.1 P m m 2

'026:P 2c -2' C2v.2 P m c 21

'027:P 2 -2c' C2v.3 P c c 2

'028:P 2 -2a' C2v.4 P m a 2

'029:P 2c -2ac' C2v.5 P c a 21

'030:P 2 -2bc' C2v.6 P n c 2

'031:P 2ac -2' C2v.7 P m n 21

'032:P 2 -2ab' C2v.8 P b a 2

'033:P 2c -2n' C2v.9 P n a 21

'034:P 2 -2n' C2v.10 P n n 2

'035:C 2 -2' C2v.11 C m m 2

'036:C 2c -2' C2v.12 C m c 21

'037:C 2 -2c' C2v.13 C c c 2

'038:A 2 -2' C2v.14 A m m 2

'039:A 2 -2b' C2v.15 A e m 2

'040:A 2 -2a' C2v.16 A m a 2

'041:A 2 -2ab' C2v.17 A e a 2

'042:F 2 -2' C2v.18 F m m 2

'043:F 2 -2d' C2v.19 F d d 2

'044:I 2 -2' C2v.20 I m m 2

'045:I 2 -2c' C2v.21 I b a 2

'046:I 2 -2a' C2v.22 I m a 2

'047:-P 2 2' D2h.1 P m m m

'048:-P 2ab 2bc' D2h.2 P n n n:2

'049:-P 2 2c' D2h.3 P c c m

'050:-P 2ab 2b' D2h.4 P b a n:2

'051:-P 2a 2a' D2h.5 P m m a

'052:-P 2a 2bc' D2h.6 P n n a

'053:-P 2ac 2' D2h.7 P m n a

'054:-P 2a 2ac' D2h.8 P c c a

'055:-P 2 2ab' D2h.9 P b a m

'056:-P 2ab 2ac' D2h.10 P c c n

'057:-P 2c 2b' D2h.11 P b c m

'058:-P 2 2n' D2h.12 P n n m

'059:-P 2ab 2a' D2h.13 P m m n:2

'060:-P 2n 2ab' D2h.14 P b c n

'061:-P 2ac 2ab' D2h.15 P b c a

'062:-P 2ac 2n' D2h.16 P n m a

'063:-C 2c 2' D2h.17 C m c m

'064:-C 2ac 2' D2h.18 C m c e

'065:-C 2 2' D2h.19 C m m m

'066:-C 2 2c' D2h.20 C c c m

'067:-C 2a 2' D2h.21 C m m e

'068:-C 2a 2ac' D2h.22 C c c e:2

'069:-F 2 2' D2h.23 F m m m

'070:-F 2uv 2vw' D2h.24 F d d d:2

'071:-I 2 2' D2h.25 I m m m

'072:-I 2 2c' D2h.26 I b a m

'073:-I 2b 2c' D2h.27 I b c a

'074:-I 2b 2' D2h.28 I m m a

'075:P 4' C4.1 P 4

'076:P 4w' C4.2 P 41

'077:P 4c' C4.3 P 42

'078:P 4cw' C4.4 P 43

'079:I 4' C4.5 I 4

'080:I 4bw' C4.6 I 41

'081:P -4' S4.1 P -4

'082:I -4' S4.2 I -4

'083:-P 4' C4h.1 P 4/m

'084:-P 4c' C4h.2 P 42/m

'085:-P 4a' C4h.3 P 4/n:2

'086:-P 4bc' C4h.4 P 42/n:2

'087:-I 4' C4h.5 I 4/m

'088:-I 4ad' C4h.6 I 41/a:2

'089:P 4 2' D4.1 P 4 2 2

'090:P 4ab 2ab' D4.2 P 4 21 2

'091:P 4w 2c' D4.3 P 41 2 2

'092:P 4abw 2nw' D4.4 P 41 21 2

'093:P 4c 2' D4.5 P 42 2 2

'094:P 4n 2n' D4.6 P 42 21 2

'095:P 4cw 2c' D4.7 P 43 2 2

'096:P 4nw 2abw' D4.8 P 43 21 2

'097:I 4 2' D4.9 I 4 2 2

'098:I 4bw 2bw' D4.10 I 41 2 2

'099:P 4 -2' C4v.1 P 4 m m

'100:P 4 -2ab' C4v.2 P 4 b m

'101:P 4c -2c' C4v.3 P 42 c m

'102:P 4n -2n' C4v.4 P 42 n m

'103:P 4 -2c' C4v.5 P 4 c c

'104:P 4 -2n' C4v.6 P 4 n c

'105:P 4c -2' C4v.7 P 42 m c

'106:P 4c -2ab' C4v.8 P 42 b c

'107:I 4 -2' C4v.9 I 4 m m

'108:I 4 -2c' C4v.10 I 4 c m

'109:I 4bw -2' C4v.11 I 41 m d

'110:I 4bw -2c' C4v.12 I 41 c d

'111:P -4 2' D2d.1 P -4 2 m

'112:P -4 2c' D2d.2 P -4 2 c

'113:P -4 2ab' D2d.3 P -4 21 m

'114:P -4 2n' D2d.4 P -4 21 c

'115:P -4 -2' D2d.5 P -4 m 2

'116:P -4 -2c' D2d.6 P -4 c 2

'117:P -4 -2ab' D2d.7 P -4 b 2

'118:P -4 -2n' D2d.8 P -4 n 2

'119:I -4 -2' D2d.9 I -4 m 2

'120:I -4 -2c' D2d.10 I -4 c 2

'121:I -4 2' D2d.11 I -4 2 m

'122:I -4 2bw' D2d.12 I -4 2 d

'123:-P 4 2' D4h.1 P 4/m m m

'124:-P 4 2c' D4h.2 P 4/m c c

'125:-P 4a 2b' D4h.3 P 4/n b m:2

'126:-P 4a 2bc' D4h.4 P 4/n n c:2

'127:-P 4 2ab' D4h.5 P 4/m b m

'128:-P 4 2n' D4h.6 P 4/m n c

'129:-P 4a 2a' D4h.7 P 4/n m m:2

'130:-P 4a 2ac' D4h.8 P 4/n c c:2

'131:-P 4c 2' D4h.9 P 42/m m c

'132:-P 4c 2c' D4h.10 P 42/m c m

'133:-P 4ac 2b' D4h.11 P 42/n b c:2

'134:-P 4ac 2bc' D4h.12 P 42/n n m:2

'135:-P 4c 2ab' D4h.13 P 42/m b c

'136:-P 4n 2n' D4h.14 P 42/m n m

'137:-P 4ac 2a' D4h.15 P 42/n m c:2

'138:-P 4ac 2ac' D4h.16 P 42/n c m:2

'139:-I 4 2' D4h.17 I 4/m m m

'140:-I 4 2c' D4h.18 I 4/m c m

'141:-I 4bd 2' D4h.19 I 41/a m d:2

'142:-I 4bd 2c' D4h.20 I 41/a c d:2

'143:P 3' C3.1 P 3

'144:P 31' C3.2 P 31

'145:P 32' C3.3 P 32

'146:R 3' C3.4 R 3:h

'147:-P 3' C3i.1 P -3

'148:-R 3' C3i.2 R -3:h

'149:P 3 2' D3.1 P 3 1 2

'150:P 3 2"' D3.2 P 3 2 1

'151:P 31 2 (0 0 4)' D3.3 P 31 1 2

'152:P 31 2"' D3.4 P 31 2 1

'153:P 32 2 (0 0 2)' D3.5 P 32 1 2

'154:P 32 2"' D3.6 P 32 2 1

'155:R 3 2"' D3.7 R 3 2:h

'156:P 3 -2"' C3v.1 P 3 m 1

'157:P 3 -2' C3v.2 P 3 1 m

'158:P 3 -2"c' C3v.3 P 3 c 1

'159:P 3 -2c' C3v.4 P 3 1 c

'160:R 3 -2"' C3v.5 R 3 m:h

'161:R 3 -2"c' C3v.6 R 3 c:h

'162:-P 3 2' D3d.1 P -3 1 m

'163:-P 3 2c' D3d.2 P -3 1 c

'164:-P 3 2"' D3d.3 P -3 m 1

'165:-P 3 2"c' D3d.4 P -3 c 1

'166:-R 3 2"' D3d.5 R -3 m:h

'167:-R 3 2"c' D3d.6 R -3 c:h

'168:P 6' C6.1 P 6

'169:P 61' C6.2 P 61

'170:P 65' C6.3 P 65

'171:P 62' C6.4 P 62

'172:P 64' C6.5 P 64

'173:P 6c' C6.6 P 63

'174:P -6' C3h.1 P -6

'175:-P 6' C6h.1 P 6/m

'176:-P 6c' C6h.2 P 63/m

'177:P 6 2' D6.1 P 6 2 2

'178:P 61 2 (0 0 5)' D6.2 P 61 2 2

'179:P 65 2 (0 0 1)' D6.3 P 65 2 2

'180:P 62 2 (0 0 4)' D6.4 P 62 2 2

'181:P 64 2 (0 0 2)' D6.5 P 64 2 2

'182:P 6c 2c' D6.6 P 63 2 2

'183:P 6 -2' C6v.1 P 6 m m

'184:P 6 -2c' C6v.2 P 6 c c

'185:P 6c -2' C6v.3 P 63 c m

'186:P 6c -2c' C6v.4 P 63 m c

'187:P -6 2' D3h.1 P -6 m 2

'188:P -6c 2' D3h.2 P -6 c 2

'189:P -6 -2' D3h.3 P -6 2 m

'190:P -6c -2c' D3h.4 P -6 2 c

'191:-P 6 2' D6h.1 P 6/m m m

'192:-P 6 2c' D6h.2 P 6/m c c

'193:-P 6c 2' D6h.3 P 63/m c m

'194:-P 6c 2c' D6h.4 P 63/m m c

'195:P 2 2 3' T.1 P 2 3

'196:F 2 2 3' T.2 F 2 3

'197:I 2 2 3' T.3 I 2 3

'198:P 2ac 2ab 3' T.4 P 21 3

'199:I 2b 2c 3' T.5 I 21 3

'200:-P 2 2 3' Th.1 P m -3

'201:-P 2ab 2bc 3' Th.2 P n -3:2

'202:-F 2 2 3' Th.3 F m -3

'203:-F 2uv 2vw 3' Th.4 F d -3:2

'204:-I 2 2 3' Th.5 I m -3

'205:-P 2ac 2ab 3' Th.6 P a -3

'206:-I 2b 2c 3' Th.7 I a -3

'207:P 4 2 3' O.1 P 4 3 2

'208:P 4n 2 3' O.2 P 42 3 2

'209:F 4 2 3' O.3 F 4 3 2

'210:F 4d 2 3' O.4 F 41 3 2

'211:I 4 2 3' O.5 I 4 3 2

'212:P 4acd 2ab 3' O.6 P 43 3 2

'213:P 4bd 2ab 3' O.7 P 41 3 2

'214:I 4bd 2c 3' O.8 I 41 3 2

'215:P -4 2 3' Td.1 P -4 3 m

'216:F -4 2 3' Td.2 F -4 3 m

'217:I -4 2 3' Td.3 I -4 3 m

'218:P -4n 2 3' Td.4 P -4 3 n

'219:F -4a 2 3' Td.5 F -4 3 c

'220:I -4bd 2c 3' Td.6 I -4 3 d

'221:-P 4 2 3' Oh.1 P m -3 m

'222:-P 4a 2bc 3' Oh.2 P n -3 n:2

'223:-P 4n 2 3' Oh.3 P m -3 n

'224:-P 4bc 2bc 3' Oh.4 P n -3 m:2

'225:-F 4 2 3' Oh.5 F m -3 m

'226:-F 4a 2 3' Oh.6 F m -3 c

'227:-F 4vw 2vw 3' Oh.7 F d -3 m:2

'228:-F 4ud 2vw 3' Oh.8 F d -3 c:2

'229:-I 4 2 3' Oh.9 I m -3 m

'230:-I 4bd 2c 3' Oh.10 I a -3 d

Category: space_group