Character table for the C_11v point group

C11v    E       2 C11   2 C11^2 2 C11^3 2 C11^4 2 C11^5 11 sv      <R> <p> <—d—> <——f——> <———g———> <————h————> <—————i—————> 
A1      1.0000  1.0000  1.0000  1.0000  1.0000  1.0000  1.0000     ... ..T ....T ......T ........T ..........T ............T
A2      1.0000  1.0000  1.0000  1.0000  1.0000  1.0000 -1.0000     ..T ... ..... ....... ......... ........... .............
E1      2.0000  1.6825  0.8308 -0.2846 -1.3097 -1.9189  0.0000     TT. TT. ..TT. ....TT. ......TT. ........TT. ..........TT.
E2      2.0000  0.8308 -1.3097 -1.9189 -0.2846  1.6825  0.0000     ... ... TT... ..TT... ....TT... ......TT... ........TT...
E3      2.0000 -0.2846 -1.9189  0.8308  1.6825 -1.3097  0.0000     ... ... ..... TT..... ..TT..... ....TT..... ......TT.....
E4      2.0000 -1.3097 -0.2846  1.6825 -1.9189  0.8308  0.0000     ... ... ..... ....... TT....... ..TT....... ....TT.......
E5      2.0000 -1.9189  1.6825 -1.3097  0.8308 -0.2846  0.0000     ... ... ..... ....... ......... TT......... TTTT.........

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



 Symmetry of Rotations and Cartesian products

A1   p+d+f+g+h+i+j+k+l+m     z, z2, z3, z4, z5, z6 
A2   R                       Rz 
E1   R+p+d+f+g+h+i+j+k+l+2m  {Rx, Ry}, {x, y}, {xz, yz}, {xz2, yz2}, {xz3, yz3}, {xz4, yz4}, {xz5, yz5} 
E2   d+f+g+h+i+j+k+2l+2m     {x2−y2, xy}, {z(x2−y2), xyz}, {z2(x2−y2), xyz2}, {z3(x2−y2), xyz3}, {z4(x2−y2), xyz4} 
E3   f+g+h+i+j+2k+2l+2m      {x(x2−3y2), y(3x2−y2)}, {xz(x2−3y2), yz(3x2−y2)}, {xz2(x2−3y2), yz2(3x2−y2)}, {xz3(x2−3y2), yz3(3x2−y2)} 
E4   g+h+i+2j+2k+2l+2m       {(x2−y2)2−4x2y2, xy(x2−y2)}, {z((x2−y2)2−4x2y2), xyz(x2−y2)}, {z2((x2−y2)2−4x2y2), xyz2(x2−y2)} 
E5   h+2i+2j+2k+2l+2m        {x(x2−(5+2√5)y2)(x2−(5−2√5)y2), y((5+2√5)x2−y2)((5−2√5)x2−y2)}, {x2(x2−3y2)2−y2(3x2−y2)2, xy(x2−3y2)(3x2−y2)}, {xz(x2−(5+2√5)y2)(x2−(5−2√5)y2), yz((5+2√5)x2−y2)((5−2√5)x2−y2)} 

 Notes:

    α  The order of the C11v point group is 22, and the order of the principal axis (C11) is 11. The group has 7 irreducible representations.

    β  The C11v point group is isomorphic to D11.

    γ  The C11v point group is generated by two symmetry elements, C11 and any σv.
       Also, the group may be generated from any two σv planes.

    δ  The group contains one set of symmetry planes σv intersecting in the principal (z) axis. The xz plane (but not the yz plane) is a member of that set.

    ε  The lowest nonvanishing multipole moment in C11v is 2 (dipole moment).

    ζ  This point group is non-Abelian (some symmetry operations are not commutative).
       Therefore, the character table contains multi-membered classes and degenerate irreducible representations.

    η  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 just 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.

    θ  The regular hendecagon is the smallest regular polygon not constructible with ruler, compass and angle trisector.
       This is because 2*cos(2*π/11) has algebraic degree of five, being the solution of an irreducible quintic equation.
       Because this quintic equation is solvable, the value of cos(2*π/11) can be expressed using square and fifth roots and complex numbers.
       That algebraic form is, however, very complex and thus not shown here.