# How can we be using the orbital model to calculate such microscale phenomena as Zeeman effect?

Surely it begs for a quantum-mechanical description? Thank you.

• Classical mechanics + magnetic fields usually predict the very same thing as Quantum mechanics to first order in perturbation theory. You can see this by the fact that most QM predictions for magnetic phenomena don't include $\hbar$ anywhere (unlike electric phenomena, such as the Stark effect). Some more details can be found in Why are electrons treated classically in cyclotron measurements? – AccidentalFourierTransform Nov 20 '16 at 20:05
• @AccidentalFourierTransform Hello! Thanks for answering. This makes sense now. Also, the best username I've seen in a while :) – Yuri Kotsar Nov 20 '16 at 21:00