Cmcm No. 63 C2/m2/c21/m D2h17


Axes Coordinates Wyckoff positions
4a 4b 4c 8d 8e 8f 8g 16h
I Maximal translationengleiche subgroups
[2] C2cm (40) 4a 4a 4b 8c 2 × 4a 8c 2 × 4b 2 × 8c
[conventional setting]Ama2 c, b, -a z, y, -x
[2] Cm2m (38) x, y, z + (1/4) 4c 4c 2a; 2b 8f 8f 2 × 4c 4d; 4e 2 × 8f
[conventional setting]Amm2 c, a, b z + (1/4), x, y
[2] Cmc21 (36) 4a 4a 4a 8b 8b 2 × 4a 8b 2 × 8b
[2] C2221 (20) 4a 4a 4b 8c 2 × 4a 8c 8c 2 × 8c
[2] C12/c1 (15) 4a 4b 4e 4c; 4d 8f 8f 8f 2 × 8f
[2] C2/m11 (12) 2a; 2c 2b; 2d 4i 4e; 4f 4g; 4h 2 × 4i 8j 2 × 8j
[conventional setting]C12/m1 b, -a, c y, -x, z
[2] P1121/m a, (1/2)(-a + b), c x + y, 2y, z 2a 2c 2e 2b; 2d 4f 4f 2 × 2e 2 × 4f
  (11) or: (1/2)(a - b), b, c 2x, x + y, z 2a 2b 2e 2c; 2d 4f 4f 2 × 2e 2 × 4f
or: (1/2)(a - b), x - y, x + y, z 2a 2d 2e 2b; 2c 4f 4f 2 × 2e 2 × 4f
(1/2)(a + b), c
II Maximal klassengleiche subgroups
   Loss of centring translations
[2] Pbnm (62) 4a 4b 4c 8d 8d 8d 2 × 4c 2 × 8d
[conventional setting]Pnma b, c, a y, z, x
[2] Pmcn (62) x + (1/4), y + (1/4), z 4c 4c 4c 4a; 4b 8d 2 × 4c 8d 2 × 8d
[conventional setting]Pnma c, a, b z, x + (1/4), y + (1/4)
[2] Pbcn (60) 4a 4b 4c 8d 8d 8d 8d 2 × 8d
[2] Pmnm (59) origin 1: x, y + (1/4), z + (1/4) 4f 4f 2a; 2b 4c; 4d 8g 2 × 4f 2 × 4e 2 × 8g
origin 2: x - (1/4), y + (1/4), z
[conventional setting]Pmmn c, a, b z + (1/4), x, y + (1/4)(origin 1)
z, x - (1/4), y + (1/4)(origin 2)
[2] Pmnn (58) 2a; 2c 2b; 2d 4g 8h 4e; 4f 2 × 4g 8h 2 × 8h
[conventional setting]Pnnm b, c, a y, z, x
[2] Pbcm (57) x + (1/4), y + (1/4), z 4c 4c 4d 4a; 4b 2 × 4c 8e 2 × 4d 2 × 8e
[2] Pbnn (52) x + (1/4), y + (1/4), z 4c 4c 4d 4a; 4b 2 × 4c 8e 8e 2 × 8e
[conventional setting]Pnna b, c, a y + (1/4), z, x + (1/4)
[2] Pmcm (51) 2a; 2d 2b; 2c 2e; 2f 8l 4g; 4h 4i; 4j 2 × 4k 2 × 8l
[conventional setting]Pmma c, a, b z, x, y
   Enlarged unit cell, isomorphic
[3] Cmcm 3a, b, c (1/3)x, y, z; ±((1/3), 0, 0) 4a; 8e 4b; 8e 4c; 8g 8d; 16h 3 × 8e 8f; 16h 3 × 8g 3 × 16h
[p] Cmcm pa, b, c (1/3)x, y, z; +((u/p), 0, 0) 4a; 4b; 4c; 8d; p × 8e 8f; p × 8g p × 16h
p = prime > 2; u = 1, . . ., p - 1 ((p - 1)/2) × 8e ((p - 1)/2) × 8e ((p - 1)/2) × 8g ((p - 1)/2) × 16h ((p - 1)/2) × 16h
[3] Cmcm a, 3b, c x, (1/3)y, z; ±(0, (1/3), 0) 4a; 8f 4b; 8f 3 × 4c 8d; 16h 8e; 16h 3 × 8f 3 × 8g 3 × 16h
[p] Cmcm a, pb, c x, (1/p)y, z; +(0, (u/p), 0) 4a; 4b; p × 4c 8d; 8e; p × 8f p × 8g p × 16h
p = prime > 2; u = 1, . . ., p - 1 ((p - 1)/2) × 8f ((p - 1)/2) × 8f ((p - 1)/2) × 16h ((p - 1)/2) × 16h
[3] Cmcm a, b, 3c x, y, (1/3)z; ±(0, 0, (1/3)) 4a; 8f 4b; 8f 4c; 8f 8d; 16h 8e; 16h 3 × 8f 8g; 16h 3 × 16h
[p] Cmcm a, b, pc x, y, (1/p)z; +(0, 0, (u/p)) 4a; 4b; 4c; 8d; 8e; p × 8f 8g; p × 16h
p = prime > 2; u = 1, . . ., p - 1 ((p - 1)/2) × 8f ((p - 1)/2) × 8f ((p - 1)/2) × 8f ((p - 1)/2) × 16h ((p - 1)/2) × 16h ((p - 1)/2) × 16h


Nonconventional settings
        interchange letters and sequences in Hermann-Mauguin symbols, axes and coordinates:
Amma CA; AB abca abca xyzx
Bbmm CB; AC abca abca xyzx
Ccmm AB a<-> b a<-> -b x<-> -y
Amam C <-> A a<-> c a<-> -c x<-> -z
Bmmb CB b<-> c b<-> -c y<-> -z










































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