Atom in Magnetic Field
Energy levels of the Hydrogen atom in a uniform magnetic field depend on the magnetic quantum number, while the eigenfunctions keep their form in a special basis. This dependence perfectly explains the (normal) Zeeman splitting of spectral lines.
The magnetic moment of the Hydrogen atom in a stationary state expresses as an integral of the corresponding electric current. The integral splits in two summands, of which one is responsible for diamagnetism resulting in the Langevin formula for diamagnetic susceptibility, and the second one is responsible for paramagnetism.
- 7.R. Becker, Electromagnetic Fields and Interactions, Vol. I, II: Quantum Theory of Atoms and Radiation (Blaisdell, Boston, 1964) Google Scholar