Origin on m m 2
| Asymmetric unit | 0 ≤ x ≤ 1/2; 0 ≤ y ≤ 1/2; 0 ≤ z ≤ 1/2 |
For (0, 0, 0)+ set
| (1) 1 | (2) 2 0, 0, z | (3) m x, 0, z | (4) m 0, y, z |
For (0, 1/2, 1/2)+ set
| (1) t(0, 1/2, 1/2) | (2) 2(0, 0, 1/2) 0, 1/4, z | (3) c x, 1/4, z | (4) n(0, 1/2, 1/2) 0, y, z |
Generators selected (1); t(1, 0, 0); t(0, 1, 0); t(0, 0, 1); t(0, 1/2, 1/2); (2); (3)
Multiplicity, Wyckoff letter,
Site symmetry | Coordinates | Reflection conditions |
| | (0, 0, 0)+ (0, 1/2, 1/2)+ | General:
|
| | (1) x, y, z | (2) -x, -y, z | (3) x, -y, z | (4) -x, y, z |
| hkl : k + l = 2n
0kl : k + l = 2n
h0l : l = 2n
hk0 : k = 2n
0k0 : k = 2n
00l : l = 2n
|
| | | Special: as above, plus
|
| | no extra conditions |
| | no extra conditions |
| | no extra conditions |
| | no extra conditions |
| | no extra conditions |
Symmetry of special projections
Along [001] p2mm
a' = a b' = 1/2b
Origin at 0, 0, z | Along [100] c1m1
a' = b b' = c
Origin at x, 0, 0 | Along [010] p11m
a' = 1/2c b' = a
Origin at 0, y, 0 |
Maximal non-isomorphic subgroups
| I | | [2] A1m1 (Cm, 8) | (1; 3)+ |
| | | [2] Am11 (Pm, 6) | (1; 4)+ |
| | | [2] A112 (C2, 5) | (1; 2)+ |
| IIa | | [2] Pnm21 (Pmn21, 31) | 1; 3; (2; 4) + (0, 1/2, 1/2) |
| | | [2] Pnc2 (30) | 1; 2; (3; 4) + (0, 1/2, 1/2) |
| | | [2] Pmc21 (26) | 1; 4; (2; 3) + (0, 1/2, 1/2) |
| | | [2] Pmm2 (25) | 1; 2; 3; 4 |
| IIb | [2] Ima2 (a' = 2a) (46); [2] Imm2 (a' = 2a) (44); [2] Ama2 (a' = 2a) (40) |
Maximal isomorphic subgroups of lowest index
| IIc | [2] Amm2 (a' = 2a) (38); [3] Amm2 (b' = 3b) (38); [3] Amm2 (c' = 3c) (38) |
Minimal non-isomorphic supergroups
| I | [2] Cmcm (63); [2] Cmmm (65); [3] P-6m2 (187); [3] P-62m (189) |
| II | [2] Fmm2 (42); [2] Pmm2 (b' = 1/2b, c' = 1/2c) (25) |
