WEB TUTORIAL - Group Theory

H2O Worked Example
The Number of Unchanged Bonds ( R)

C2vEC2 (z)sigmav(xz)sigmav(yz)Linear functions,
rotations
Quadratic
functions
Cubic
functions
A1+1+1+1+1zx2, y2, z2z3, x2z, y2z
A2+1+1-1-1Rzxyxyz
B1+1-1+1-1x, Ryxzxz2, x3, xy2
B2+1-1-1+1y, Rxyzyz2, y3, x2y
Number of symmetry elements, h = 4

You must consider the bonds which have moved, and hence how many bonds remain unchanged after the symmetry element has been completed. Not the atoms!

E.g. C2 rotation:
One atom has stayed in the same position, but imagine the bonds are labelled 'A' and 'B'. Thus following around the pictures, you can see that bond 'A' and bond 'B' have changed positions, hence for C2 rotation there are NO Unchanged bonds.

Consider each symmetry element in turn, and answer how many unchanged bonds there are in each case after the symmetry element has been completed and pick one of the following answers.

The first number indicates the number of unchanged bonds for E, the second number
indicates the number of unchanged bonds for the C2 rotation and so forth.