1. The problem statement, all variables and given/known data Determine the point group of the chair conformer of cyclohexane. How many Raman active vibrations and how many infra-red active vibrations might you expect to detect in its spectrum? 2. Relevant equations (see link below) 3. The attempt at a solution http://img442.imageshack.us/img442/240/symmetrycw.jpg Im rubbish with LaTex so ive hosted a picture of what ive done in word. Ive determined the point group to be D3h but when I use the equation to get the values for the different vibrations, I get a total of 24 when it should be 18 because I started with 18 vectors (3 on each carbon). Im not sure where im going wrong. Thanks.