Character table for the C22 point group

C22     E       2 C22   2 C11   2 C22^3 2 C11^2 2 C22^5 2 C11^3 2 C22^7 2 C11^4 2 C22^9 2 C11^5 C2         <R> <p> <—d—> <——f——> <———g———> <————h————> <—————i—————> 
A       1.0000  1.0000  1.0000  1.0000  1.0000  1.0000  1.0000  1.0000  1.0000  1.0000  1.0000  1.0000     ..T ..T ....T ......T ........T ..........T ............T
B       1.0000 -1.0000  1.0000 -1.0000  1.0000 -1.0000  1.0000 -1.0000  1.0000 -1.0000  1.0000 -1.0000     ... ... ..... ....... ......... ........... .............
E1  *   2.0000  1.9189  1.6825  1.3097  0.8308  0.2846 -0.2846 -0.8308 -1.3097 -1.6825 -1.9189 -2.0000     TT. TT. ..TT. ....TT. ......TT. ........TT. ..........TT.
E2  *   2.0000  1.6825  0.8308 -0.2846 -1.3097 -1.9189 -1.9189 -1.3097 -0.2846  0.8308  1.6825  2.0000     ... ... TT... ..TT... ....TT... ......TT... ........TT...
E3  *   2.0000  1.3097 -0.2846 -1.6825 -1.9189 -0.8308  0.8308  1.9189  1.6825  0.2846 -1.3097 -2.0000     ... ... ..... TT..... ..TT..... ....TT..... ......TT.....
E4  *   2.0000  0.8308 -1.3097 -1.9189 -0.2846  1.6825  1.6825 -0.2846 -1.9189 -1.3097  0.8308  2.0000     ... ... ..... ....... TT....... ..TT....... ....TT.......
E5  *   2.0000  0.2846 -1.9189 -0.8308  1.6825  1.3097 -1.3097 -1.6825  0.8308  1.9189 -0.2846 -2.0000     ... ... ..... ....... ......... TT......... ..TT.........
E6  *   2.0000 -0.2846 -1.9189  0.8308  1.6825 -1.3097 -1.3097  1.6825  0.8308 -1.9189 -0.2846  2.0000     ... ... ..... ....... ......... ........... TT...........
E7  *   2.0000 -0.8308 -1.3097  1.9189 -0.2846 -1.6825  1.6825  0.2846 -1.9189  1.3097  0.8308 -2.0000     ... ... ..... ....... ......... ........... .............
E8  *   2.0000 -1.3097 -0.2846  1.6825 -1.9189  0.8308  0.8308 -1.9189  1.6825 -0.2846 -1.3097  2.0000     ... ... ..... ....... ......... ........... .............
E9  *   2.0000 -1.6825  0.8308  0.2846 -1.3097  1.9189 -1.9189  1.3097 -0.2846 -0.8308  1.6825 -2.0000     ... ... ..... ....... ......... ........... .............
E10 *   2.0000 -1.9189  1.6825 -1.3097  0.8308 -0.2846 -0.2846  0.8308 -1.3097  1.6825 -1.9189  2.0000     ... ... ..... ....... ......... ........... .............

 Irrational character values:  1.918985947229 = 2*cos(2*π/22) = 2*cos(π/11)
                               1.682507065662 = 2*cos(4*π/22) = 2*cos(2*π/11)
                               1.309721467891 = 2*cos(6*π/22) = 2*cos(3*π/11)
                               0.830830026004 = 2*cos(8*π/22) = 2*cos(4*π/11)
                               0.284629676547 = 2*cos(10*π/22) = 2*cos(5*π/11)



 Symmetry of Rotations and Cartesian products

A    R+p+d+f+g+h+i+j+k+l+m  Rz, z, z2, z3, z4, z5, z6 
E1   R+p+d+f+g+h+i+j+k+l+m  {Rx, Ry}, {x, y}, {xz, yz}, {xz2, yz2}, {xz3, yz3}, {xz4, yz4}, {xz5, yz5} 
E2   d+f+g+h+i+j+k+l+m      {x2y2, xy}, {z(x2y2), xyz}, {z2(x2y2), xyz2}, {z3(x2y2), xyz3}, {z4(x2y2), xyz4} 
E3   f+g+h+i+j+k+l+m        {x(x2−3y2), y(3x2y2)}, {xz(x2−3y2), yz(3x2y2)}, {xz2(x2−3y2), yz2(3x2y2)}, {xz3(x2−3y2), yz3(3x2y2)} 
E4   g+h+i+j+k+l+m          {(x2y2)2−4x2y2, xy(x2y2)}, {z((x2y2)2−4x2y2), xyz(x2y2)}, {z2((x2y2)2−4x2y2), xyz2(x2y2)} 
E5   h+i+j+k+l+m            {x(x2−(5+2√5)y2)(x2−(5−2√5)y2), y((5+2√5)x2y2)((5−2√5)x2y2)}, {xz(x2−(5+2√5)y2)(x2−(5−2√5)y2), yz((5+2√5)x2y2)((5−2√5)x2y2)} 
E6   i+j+k+l+m              {x2(x2−3y2)2y2(3x2y2)2, xy(x2−3y2)(3x2y2)} 
E7   j+k+l+m 
E8   k+l+m 
E9   l+m 
E10  m 

 Notes:

    α  The order of the C22 point group is 22, and the order of the principal axis (C22) is 22. The group has 12 irreducible representations.

    β  The C22 point group is isomorphic to S22 and C11h.

    γ  The C22 point group is generated by one single symmetry element, C22. Therefore, it is a cyclic group.

    δ  The lowest nonvanishing multipole moment in C22 is 2 (dipole moment).

    ε  This is an Abelian point group (the commutative law holds between all symmetry operations).
       The C22 group is Abelian because it contains only one symmetry element, all the powers of which necessarily commute (sufficient condition).
       In Abelian groups, all symmetry operations form a class of their own, and all irreducible representations are one-dimensional.

    ζ  Because the group is Abelian and the maximum order of rotation is >2, some irreducible representations have complex characters.
       These 20 cases have been combined into 10 two-dimensional representations that are no longer irreducible but have real-valued characters.
       Accordingly, 10 pairs of left and right rotations have been combined into one two-membered pseudo-class each.

    η  The 10 reducible “E” representations almost behave like true irreducible representations.
       Their norm, however, is twice the group order. Therefore, they have been marked with an asterisk in the table.
       This is essential when trying to decompose a reducible representation into “irreducible” ones using the familiar projection formula.

    θ  The point group is chiral, as it does not contain any mirroring operation.

    ι  Some of the characters in the table are irrational because the order of the principal axis is neither 1,2,3,4 nor 6.
       These irrational values can be expressed as cosine values, or as solutions of algebraic equations with a leading coefficient of 1.
       All characters are algebraic integers of a degree much less than half the order of the principal axis.
       For this group, however, none of the irrational characters can be expressed by a closed algebraic form using real numbers only.

This Character Table for the C22 point group was created by Gernot Katzer.

For other groups and some explanations, see the Main Page.