Pmc21 No. 26 C2v2


Axes Coordinates Wyckoff positions
2a 2b 4c
I Maximal translationengleiche subgroups
[2] P1c1 (7) 2a 2a 2 × 2a
[2] Pm11 (6) 2 × 1a 2 × 1b 2 × 2c
[conventional setting]P1m1 c, a, b z, x, y
[2] P1121 (4) 2a 2a 2 × 2a
II Maximal klassengleiche subgroups
   Enlarged unit cell, non-isomorphic
[2] Cmc21 (36) 2a, 2b, c (1/2)x, (1/2)y, z; +((1/2), 0, 0) 2 × 4a 8b 2 × 8b
[2] Cmc21 (36) 2a, 2b, c (1/2)x + (1/4), (1/2)y, z; +((1/2), 0, 0) 8b 2 × 4a 2 × 8b
[2] Cmc21 (36) 2a, 2b, c (1/2)x, (1/2)y + (1/4), z; +((1/2), 0, 0) 2 × 4a 8b 2 × 8b
[2] Cmc21 (36) 2a, 2b, c (1/2)x + (1/4), (1/2)y + (1/4), z; +((1/2), 0, 0) 8b 2 × 4a 2 × 8b
[2] Pmn21 (31) 2a, b, c (1/2)x, y, z; +((1/2), 0, 0) 2 × 2a 4b 2 × 4b
[2] Pmn21 (31) 2a, b, c (1/2)x + (1/4), y, z; +((1/2), 0, 0) 4b 2 × 2a 2 × 4b
[2] Pbc21 (29) a, 2b, c x, (1/2)y, z 4a 4a 2 × 4a
[conventional setting]Pca21 2b, -a, c (1/2)y, -x, z
[2] Pbc21 (29) a, 2b, c x, (1/2)y + (1/4), z 4a 4a 2 × 4a
[conventional setting]Pca21 2b, -a, c (1/2)y + (1/4), -x, z
   Enlarged unit cell, isomorphic
[2] Pmc21 2a, b, c (1/2)x, y, z; +((1/2), 0, 0) 2a; 2b 4c 2 × 4c
[2] Pmc21 2a, b, c (1/2)x + (1/4), y, z; +((1/2), 0, 0) 4c 2a; 2b 2 × 4c
[3] Pmc21 3a, b, c (1/3)x, y, z; ±((1/3), 0, 0) 2a; 4c 2b; 4c 3 × 4c
[p] Pmc21 pa, b, c (1/p)x, y, z; +((u/p), 0, 0) 2a; ((p - 1)/2) × 4c 2b; ((p - 1)/2) × 4c p × 4c
p = prime > 2; u = 1, . . ., p - 1
[2] Pmc21 a, 2b, c x, (1/2)y, z; +(0, (1/2), 0) 2 × 2a 2 × 2b 2 × 4c
[2] Pmc21 a, 2b, c x, (1/2)y + (1/4), z; +(0, (1/2), 0) 2 × 2a 2 × 2b 2 × 4c
[3] Pmc21 a, 3b, c x, (1/3)y, z; ±(0, (1/3), 0) 3 × 2a 3 × 2b 3 × 4c
[p] Pmc21 a, pb, c x, (1/p)y, z; +(0, (u/p), 0) p × 2a p × 2b p × 4c
p = prime; u = 1, . . ., p - 1
[3] Pmc21 a, b, 3c x, y, (1/3)z; ±(0, 0, (1/3)) 3 × 2a 3 × 2b 3 × 4c
[p] Pmc21 a, b, pc x, y, (1/p)y; +(0, 0, (u/p)) p × 2a p × 2b p × 4c
p = prime > 2; u = 1, . . ., p - 1


Nonconventional settings
        interchange letters and sequences in Hermann-Mauguin symbols, axes and coordinates:
P21ma C → A a→ b → c → a a → b → c → a x→ y → z → x
Pb21m B ← C a← b ← c ← a a← b ← c ← a x← y ← z ← x
Pcm21 a<-> b a<-> -b x<-> -y
P21am C→ A a<-> c a<-> -c x<-> -z
Pm21b B← C b<-> c b<-> -c y<-> -z









































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