C2h E C2 i sh <R> <p> <—d—> <——f——> <———g———> <————h————> <—————i—————> Ag 1 1 1 1 ..T ... TT..T ....... TT..TT..T ........... TT..TT..TT..T Bg 1 -1 1 -1 TT. ... ..TT. ....... ..TT..TT. ........... ..TT..TT..TT. Au 1 1 -1 -1 ... ..T ..... ..TT..T ......... ..TT..TT..T ............. Bu 1 -1 -1 1 ... TT. ..... TT..TT. ......... TT..TT..TT. ............. Symmetry of Rotations and Cartesian products Ag R+3d+5g+7i+9k+11m R_{z}, x^{2}−y^{2}, xy, z^{2}, (x^{2}−y^{2})^{2}−4x^{2}y^{2}, xy(x^{2}−y^{2}), z^{2}(x^{2}−y^{2}), xyz^{2}, z^{4}, x^{2}(x^{2}−3y^{2})^{2}−y^{2}(3x^{2}−y^{2})^{2}, xy(x^{2}−3y^{2})(3x^{2}−y^{2}), z^{2}((x^{2}−y^{2})^{2}−4x^{2}y^{2}), xyz^{2}(x^{2}−y^{2}), z^{4}(x^{2}−y^{2}), xyz^{4}, z^{6} Bg 2R+2d+4g+6i+8k+10m R_{x}, R_{y}, xz, yz, xz(x^{2}−3y^{2}), yz(3x^{2}−y^{2}), xz^{3}, yz^{3}, xz(x^{2}−(5+2√5)y^{2})(x^{2}−(5−2√5)y^{2}), yz((5+2√5)x^{2}−y^{2})((5−2√5)x^{2}−y^{2}), xz^{3}(x^{2}−3y^{2}), yz^{3}(3x^{2}−y^{2}), xz^{5}, yz^{5} Au p+3f+5h+7j+9l z, z(x^{2}−y^{2}), xyz, z^{3}, z((x^{2}−y^{2})^{2}−4x^{2}y^{2}), xyz(x^{2}−y^{2}), z^{3}(x^{2}−y^{2}), xyz^{3}, z^{5} Bu 2p+4f+6h+8j+10l x, y, x(x^{2}−3y^{2}), y(3x^{2}−y^{2}), xz^{2}, yz^{2}, x(x^{2}−(5+2√5)y^{2})(x^{2}−(5−2√5)y^{2}), y((5+2√5)x^{2}−y^{2})((5−2√5)x^{2}−y^{2}), xz^{2}(x^{2}−3y^{2}), yz^{2}(3x^{2}−y^{2}), xz^{4}, yz^{4} Notes: α The order of the C_{2h} point group is 4, and the order of the principal axis (C_{2}) is 2. The group has 4 irreducible representations. β The C_{2h} point group is isomorphic to C_{2v} and D_{2}, and also to the Klein four-group. γ The C_{2h} point group is generated by two two symmetry elements, C_{2} and i; non-canonically, by C_{2} and σ_{h} or by i and σ_{h}. δ The lowest nonvanishing multipole moment in C_{2h} is 4 (quadrupole moment). ε This is an Abelian point group (the commutative law holds between all symmetry operations). The C_{2h} group is Abelian because it meets two sufficient conditions: Its symmetry elements are coaxial, and none is of of order 3 or higher. In Abelian groups, all symmetry operations form a class of their own, and all irreducible representations are one-dimensional. ζ There are no symmetry elements of an order higher than 2 in this group. The symmetry-adapted Cartesian products in the table above are needlessly complicated; rather, any simple product will do. η All characters are integers because the order of the principal axis is 1,2,3,4 or 6. Such point groups are also referred to as “crystallographic point groups”, as they are compatible with periodic lattice symmetry. There are exactly 32 such groups: C_{1},C_{s},C_{i},C_{2},C_{2h},C_{2v},C_{3},C_{3h},C_{3v},C_{4},C_{4h},C_{4v},C_{6},C_{6h},C_{6v},D_{2},D_{2d},D_{2h},D_{3},D_{3d},D_{3h},D_{4},D_{4h},D_{6},D_{6h},S_{4},S_{6},T,T_{d},T_{h},O,O_{h}.
C_{s} | ||
C_{2} C_{2v} | C_{2h} | D_{2} D_{2h} D_{2d} C_{i} |
C_{3h} | ||
C_{4h} |
This Character Table for the C_{2h} point group was created by Gernot Katzer.
For other groups and some explanations, see the Main Page.