Electron microscopy
Monoclinic Space Groups
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In the names of monoclinic space groups, the first letter denotes the lattice type and the remaining part of the space group symbol indicates the symmetry with respect to the unique axis direction, i.e. axes parallel to the unique axis or planes perpendicular to it. Furthermore, the short form of the names of the monoclinic space groups ignore the two "1"s for the symmetry with respect to the other two axes.

As listed in Table 1470, for monoclinic space groups 3 - 15, one symbol gives the nature of the two-fold axis (rotation axis 2 or screw axis 21) or reflection plane (mirror plane m or glide plane c). Two settings are used for monoclinic space groups: y-axis unique or z-axis unique.

Table 1470. Monoclinic space groups 3 - 15.

Group number Schoenflies symbol Hermann-Mauguin (H-M) symbol  Lattice type   Group number Schoenflies symbol Hermann-Mauguin (H-M) symbol  Lattice type
3 C21 P2, P112 P 10 C2h1 P2/m P
4 C22 P21, B21, C1121, P1121, P2111 P 11 C2h2 P21/m, B21/m, P1121/m P
5 C23 C2, A112, A2, B112, F2, I2, I21 C 12 C2h3 C2/m, A112/m, A2/m, B112/m, C2/a, C2/m11, F2/m, I112/m, I2/m C
6 Cs1 Pm P 13 C2h4 P2/c, C112/b, P112/a, P112/b, P112/n, P2/a, P2/c11, P2/n P
7 Cs2 Pc, Bd, C11a, Pa, Pn, P11b, P11n P 14 C2h5 P21/c, B21/a, B21/c, B21/d, P1121/a, P1121/b, P1121/n, P21/a, P21/b11, P21/c11, P21/n, P21/n11 P
8 Cs3 Cm, Am, Im C 15 C2h6 A2/a, C2/c , A112/a, A2/n, B1121/b, B112/b, B112/n, C2/c11, C2/n, F2/d, I112/a, I112/b, I2/a, I2/c, I2/n, I21/a, I21/c C
9 Cs4 Cc, Aa, An, A11a, B11b, Cn, Fd11, Ia, Ic C