# Rotational quantum number J

1. Feb 26, 2012

### Chemist20

Is it the same as the total angular momentum quantum number ?????

2. Feb 26, 2012

### ZealScience

What do you mean? Usually, in QM, J is used to describe the total angular momentum operator and the corresponding eigenvalue, same as orbital angular momentum L

The quantum number, however, does not equal to the value of total angular momentum. Orbital angular momentum number l, for example, usually represents (I can't remember the exact notation) total of l(l+1).

3. Feb 26, 2012

### Chemist20

yeah thats what I thought! But if you look up info about microwave spectroscopy, they talk about J as rotational QN!