Pbca D2h15 mmm Orthorhombic info
No. 61 P21/b21/c21/a Patterson symmetry Pmmm

symmetry group diagram

Origin at -1

Asymmetric unit 0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ z ≤ 1/2

Symmetry operations

(1)  1   (2)  2(0, 0, 1/2)   1/4, 0, z(3)  2(0, 1/2, 0)   0, y1/4(4)  2(1/2, 0, 0)   x1/4, 0
(5)  -1   0, 0, 0(6)  a   xy1/4(7)  c   x1/4z(8)  b   1/4yz

Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); (2); (3); (5)

Positions

Multiplicity, Wyckoff letter,
Site symmetry
Coordinates Reflection conditions
 General:
8 c 1
(1) xyz(2) -x + 1/2-yz + 1/2(3) -xy + 1/2-z + 1/2(4) x + 1/2-y + 1/2-z
(5) -x-y-z(6) x + 1/2y-z + 1/2(7) x-y + 1/2z + 1/2(8) -x + 1/2y + 1/2z
0kl: k = 2n
h0l: l = 2n
hk0: h = 2n
h00: h = 2n
0k0: k = 2n
00l: l = 2n
    Special: as above, plus
4 b  -1 
0, 0, 1/2 1/2, 0, 0 0, 1/2, 0 1/21/21/2
hkl: h  +  kh  +  lk  +  l  =  2n
4 a  -1 
0, 0, 0 1/2, 0, 1/2 0, 1/21/2 1/21/2, 0
hkl: h  +  kh  +  lk  +  l  =  2n

Symmetry of special projections

Along [001]   p2gm
a' = 1/2a   b' = b   
Origin at 0, 0, z
Along [100]   p2gm
a' = 1/2b   b' = c   
Origin at x, 0, 0
Along [010]   p2gm
a' = 1/2c   b' = a   
Origin at 0, y, 0








































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