Cccm No. 66 C2/c2/c2/m D2h20


Axes Coordinates Wyckoff positions
4a 4b 4c 4d 4e 4f 8g 8h 8i 8j 8k 8l
16m
I Maximal translationengleiche subgroups
[2] C2cm (40) x, y, z + (1/4) 4a 4a 4b 4b 4b 4b 2 × 4a 8c 8c 8c 8c 2 × 4b
[conventional setting]Ama2 c, -b, a z + (1/4), -y, x 2 × 8c
[2] Cc2m (40) x, y, z + (1/4) 4a 4a 4b 4b 4b 4b 8c 2 × 4a 8c 8c 8c 2 × 4b
[conventional setting]Ama2 c, a, b z + (1/4), x, y 2 × 8c
[2] Ccc2 (37) 4a 4b 4a 4b 4c 4c 8d 8d 2 × 4a 2 × 4b 2 × 4c 8d
2 × 8d
[2] C222 (21) x, y, z + (1/4) 2a; 2d 2b; 2c 4i 4j 4k 4k 4e; 4f 4g; 4h 2 × 4i 2 × 4j 2 × 4k 8l
2 × 8l
[2] C2/c11 (15) 4e 4e 4a 4b 4c 4d 2 × 4e 8f 8f 8f 8f 8f
[conventional setting]C12/c1 b, a, -c y, x, -z 2 × 8f
[2] C12/c1 (15) 4e 4e 4a 4b 4c 4d 8f 2 × 4e 8f 8f 8f 8f
2 × 8f
[2] P112/m(10) a, (1/2)(-a + b), c x + y, 2y, z 2i 2k 1a; 1b 1c; 1f 1e; 1g 1d; 1h 4o 4o 2 × 2i 2 × 2k 2j; 2l 2m; 2n
2 × 4o
  or: (1/2)(a - b), x - y, x + y, z 2i 2l 1a; 1b 1g; 1h 1d; 1f 1c; 1e 4o 4o 2 × 2i 2 × 2l 2j; 2k 2m; 2n
(1/2)(a + b), c 2 × 4o
II Maximal klassengleiche subgroups
   Loss of centring translations
[2] Pnnm (58) 4e 4f 2a; 2b 2c; 2d 4g 4g 8h 8h 2 × 4e 2 × 4f 8h 2 × 4g
2 × 8h
[2] Pccn (56) x + (1/4), y + (1/4), z 4c 4d 4c 4d 4a 4b 8e 8e 2 × 4c 2 × 4d 8e 8e
2 × 8e
[2] Pcnm (53) x + (1/4), y + (1/4), z 4g 4g 4h 4h 2a; 2c 2b; 2d 8i 2 × 4g 8i 8i 4e; 4f 2 × 4h
[conventional setting]Pmna c, -b, a z, -y - (1/4), x + (1/4) 2 × 8i
[2] Pncm (53) x + (1/4), y + (1/4), z 4g 4g 4h 4h 2a; 2c 2b; 2d 2 × 4g 8i 8i 8i 4e; 4f 2 × 4h
[conventional setting]Pmna c, a, b z, x + (1/4), y + (1/4) 2 × 8i
[2] Pncn (52) 4c 4c 4a 4b 4d 4d 8e 2 × 4c 8e 8e 2 × 4d 8e
[conventional setting]Pnna c, a, b z, x, y 2 × 8e
[2] Pcnn (52) 4c 4c 4a 4b 4d 4d 2 × 4c 8e 8e 8e 2 × 4d 8e
[conventional setting]Pnna c, -b, a z, -y, x 2 × 8e
[2] Pccm (49) 2e; 2h 2f; 2g 2a; 2b 2c; 2d 4q 4q 4i; 4j 4k; 4l 4m; 4n 4o; 4p 8r 2 × 4q
2 × 8r
[2] Pnnn (48) origin 1: x, y, z - (1/4) 2a; 2c 2b; 2d 4k 4l 4f 4e 4g; 4h 4i; 4j 2 × 4k 2 × 4l 8m 8m
origin 2: x + (1/4), y + (1/4), z 2 × 8m


Axes Coordinates Wyckoff positions
4a 4b 4c 4d 4e 4f 8g 8h 8i
8j 8k 8l 16m
   Enlarged unit cell, isomorphic
[3] Cccm 3a, b, c (1/3)x, y, z; ±((1/3), 0, 0) 4a; 8g 4b; 8g 4c; 8l 4d; 8l 4f; 8l 4e; 8l 3 × 8g 8h; 16m 8i; 16m
8j; 16m 8k; 16m 3 × 8l 3 × 16m
[p] Cccm pa, b, c (1/p)x, y, z; +((u/p), 0, 0) 4a; 4b; 4c; 4d; 4e; 4f; p × 8g 8h; 8i;
p = prime > 2; ((p - 1)/2) × 8g ((p - 1)/2) × 8g ((p - 1)/2) × 8l ((p - 1)/2) × 8l ((p - 1)/2) × 8l ((p - 1)/2) × 8l ((p - 1)/2) × 16m ((p - 1)/2) × 16m
u = 1, . . ., p - 1 8j; 8k; p × 8l p × 16m
((p - 1)/2) × 16m ((p - 1)/2) × 16m
[3] Cccm a, 3b, c x, (1/3)y, z; ±(0, (1/3), 0) 4a; 8h 4b; 8h 4c; 8l 4d; 8l 4f; 8l 4e; 8l 8g; 16m 3 × 8h 8i; 16m
8j; 16m 8k; 16m 3 × 8l 3 × 16m
[p] Cccm a, pb, c x, (1/p)y, z; +(0, (u/p), 0) 4a; 4b; 4c; 4d; 4e; 4f; 8g; p × 8h 8i;
p = prime > 2; ((p - 1)/2) × 8h ((p - 1)/2) × 8h ((p - 1)/2) × 8l ((p - 1)/2) × 8l ((p - 1)/2) × 8l ((p - 1)/2) × 8l ((p - 1)/2) × 16m ((p - 1)/2) × 16m
u = 1, . . ., p - 1 8j; 8k; p × 8l p × 16m
((p - 1)/2) × 16m ((p - 1)/2) × 16m
[3] Cccm a, b, 3c x, y, (1/3)z; ±(0, 0, (1/3)) 4a; 8i 4b; 8j 4c; 8i 4d; 8j 4e; 8k 4f; 8k 8g; 16m 8h; 16m 3 × 8i
3 × 8j 3 × 8k 8l; 16m 3 × 16m
[p] Cccm a, b, pc x, y, (1/p)z; +(0, 0, (u/p)) 4a; 4b; 4c; 4d; 4e; 4f; 8g; 8h; p × 8i
p = prime > 2; ((p - 1)/2) × 8i ((p - 1)/2) × 8j ((p - 1)/2) × 8i ((p - 1)/2) × 8j ((p - 1)/2) × 8k ((p - 1)/2) × 8k ((p - 1)/2) × 16m ((p - 1)/2) × 16m
u = 1, . . ., p - 1 p × 8j p × 8k 8l; p × 16m
((p - 1)/2) × 16m


Nonconventional settings
        interchange letters and sequences in Hermann-Mauguin symbols, axes and coordinates:
Amaa C → A→ B a→ b → c → a a→ b → c → a x→ y → z → x
Bbmb A→ C→ B a← b ← c ← a a← b ← c ← a x← y ← z ← x









































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