Cm Cs3 m Monoclinic info
No. 8 A11m Patterson symmetry A112/m
UNIQUE AXIS c, CELL CHOICE 1

symmetry group diagram

Origin on mirror plane m

Asymmetric unit 0 ≤ x ≤ 1; 0 ≤ y ≤ 1; 0 ≤ z ≤ 1/4

Symmetry operations

For (0,  0,  0)+ set

(1)  1   (2)  m   xy, 0

For (0, 1/21/2)+ set

(1)  t(0, 1/21/2)   (2)  b   xy1/4

Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(0, 1/21/2); (2)

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions
 (0, 0, 0)+  (0, 1/21/2)+  General:
4 b 1
(1) xyz(2) xy-z
hkl : k + l = 2n
hk0 : k = 2n
0kl : k + l = 2n
h0l : l = 2n
00l : l = 2n
0k0 : k = 2n
    Special: as above, plus
2 a  m 
xy, 0
no extra conditions

Symmetry of special projections

Along [001]   p1
a' = a   b' = 1/2b   
Origin at 0, 0, z
Along [100]   c11m
a' = bp   b' = c   
Origin at x, 0, 0
Along [010]   p1m1
a' = 1/2c   b' = ap   
Origin at 0, y, 0

Maximal non-isomorphic subgroups

I [2] A1 (P1, 1)1+
IIa [2] P11b (Pc, 7)1; 2 + (0, 1/21/2)
  [2] P11m (Pm, 6)1; 2
IIb[2] A11a (a' = 2a) (Cc, 9); [2] I11a (a' = 2a) (Cc, 9)

Maximal isomorphic subgroups of lowest index

IIc[2] A11m (a' = 2a or a' = 2ab' = 2a + b) (Cm, 8); [3] A11m (c' = 3c) (Cm, 8)

Minimal non-isomorphic supergroups

I[2] C2/m (12); [2] Cmm2 (35); [2] Cmc21 (36); [2] Amm2 (38); [2] Aem2 (39); [2] Fmm2 (42); [2] Imm2 (44); [2] Ima2 (46); [3] P3m1 (156); [3] P31m (157); [3] R3m (160)
II[2] P11m (b' = 1/2b, c' = 1/2c) (Pm, 6)

UNIQUE AXIS c, DIFFERENT CELL CHOICES

symmetry group diagram

A11m

UNIQUE AXIS c, CELL CHOICE 1

cell choice

Origin on mirror plane m

Asymmetric unit 0 ≤ x ≤ 1; 0 ≤ y ≤ 1; 0 ≤ z ≤ 1/4

Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(0, 1/21/2); (2)

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions
 (0, 0, 0)+  (0, 1/21/2)+  General:
4 b 1
(1) xyz(2) xy-z
hkl : k + l = 2n
hk0 : k = 2n
0kl : k + l = 2n
h0l : l = 2n
00l : l = 2n
0k0 : k = 2n
    Special: as above, plus
2 a  m 
xy, 0
no extra conditions

B11m

UNIQUE AXIS c, CELL CHOICE 2

cell choice

Origin on mirror plane m

Asymmetric unit 0 ≤ x ≤ 1; 0 ≤ y ≤ 1; 0 ≤ z ≤ 1/4

Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(1/2, 0, 1/2); (2)

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions
 (0, 0, 0)+  (1/2, 0, 1/2)+  General:
4 b 1
(1) xyz(2) xy-z
hkl : h + l = 2n
hk0 : h = 2n
0kl : l = 2n
h0l : h + l = 2n
00l : l = 2n
h00 : h = 2n
    Special: as above, plus
2 a  m 
xy, 0
no extra conditions

I11m

UNIQUE AXIS c, CELL CHOICE 3

cell choice

Origin on mirror plane m

Asymmetric unit 0 ≤ x ≤ 1; 0 ≤ y ≤ 1; 0 ≤ z ≤ 1/4

Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(1/21/21/2); (2)

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions
 (0, 0, 0)+  (1/21/21/2)+  General:
4 b 1
(1) xyz(2) xy-z
hkl : h + k + l = 2n
hk0 : h + k = 2n
0kl : k + l = 2n
h0l : h + l = 2n
00l : l = 2n
h00 : h = 2n
0k0 : k = 2n
    Special: as above, plus
2 a  m 
xy, 0
no extra conditions








































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