# Homework Help: First order purterbation

1. May 29, 2007

### 0kensai0

1. The problem statement, all variables and given/known data

A diatomic molecule in a uiform magnetic field along z-axis B =(0,0,B). SO the Hamiltonian is $$H = \frac{\hat{l^2}}{2I} - \mu(\hat{B}\bullet\hat{i})$$

$$\mu$$ is some co-efficient. Considering he hamiltonian above as perturbation and using first order perturbation theory find an espression for energy levels of the molecule in the magnetic field and What is the degeneracy of each level

2. Relevant equations

3. The attempt at a solution

I've just been taught perturbation theory so it's still kinda confusing for me. All the problems I have done do not involve an hamiltonian of that sort and do not involve diatomic molecules so I'm not sure what the answer should be like at all.