P3c1 C3v3 3m1 Trigonal info
No. 158 P3c1 Patterson symmetry P-3m1

symmetry group diagram

Origin on 3 c 1

Asymmetric unit 0 ≤ x ≤ 2/3; 0 ≤ y ≤ 2/3; 0 ≤ z ≤ 1/2; x ≤ (1 + y)/2; y ≤ min(1 - x, (1 + x)/2)
Vertices
0, 0, 0  1/2, 0, 0  2/31/3, 0  1/32/3, 0  0, 1/2, 0  
0, 0, 1/2  1/2, 0, 1/2  2/31/31/2  1/32/31/2  0, 1/21/2  

Symmetry operations

(1)  1   (2)  3+   0, 0, z(3)  3-   0, 0, z
(4)  c   x-xz(5)  c   x, 2xz(6)  c   2xxz

Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (4)

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions
 General:
6 d 1
(1) xyz(2) -yx - yz(3) -x + y-xz
(4) -y-xz + 1/2(5) -x + yyz + 1/2(6) xx - yz + 1/2
h-h0l : l = 2n
000l : l = 2n
    Special: as above, plus
2 c  3 . . 
2/31/3z 2/31/3z + 1/2
hkil : l = 2n
2 b  3 . . 
1/32/3z 1/32/3z + 1/2
hkil : l = 2n
2 a  3 . . 
0, 0, z 0, 0, z + 1/2
hkil : l = 2n

Symmetry of special projections

Along [001]   p3m1
a' = a   b' = b   
Origin at 0, 0, z
Along [100]   p1
a' = 1/2(a + 2b)   b' = 1/2c   
Origin at x, 0, 0
Along [210]   p1g1
a' = 1/2b   b' = c   
Origin at x1/2x, 0

Maximal non-isomorphic subgroups

I [2] P311 (P3, 143)1; 2; 3
 [brace][3] P1c1 (Cc, 9)1; 4
 [3] P1c1 (Cc, 9)1; 5
 [3] P1c1 (Cc, 9)1; 6
IIa none
IIb[3] H3c1 (a' = 3ab' = 3b) (P31c, 159)

Maximal isomorphic subgroups of lowest index

IIc[3] P3c1 (c' = 3c) (158); [4] P3c1 (a' = 2ab' = 2b) (158)

Minimal non-isomorphic supergroups

I[2] P-3c1 (165); [2] P6cc (184); [2] P63cm (185); [2] P-6c2 (188)
II[3] H3c1 (P31c, 159); [3] R3c (obverse) (161); [3] R3c (reverse) (161); [2] P3m1 (c' = 1/2c) (156)








































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