How do I predict the spectrum when a magnetic field is applied on a specific transition from a term symbol to another? [closed]








**Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers.
 
 






---








 **Homework questions** must demonstrate some effort to understand the underlying concepts. For help asking a good homework question, see: [How do I ask homework questions on Chemistry Stack Exchange?](https://chemistry.meta.stackexchange.com/questions/141/how-do-i-ask-homework-questions-on-chemistry-stack-exchange)




Closed 10 months ago.








[Improve this question](/posts/169149/edit) 



More specifically the question pertains to physical/quantum chemistry, and to the transition 2D (with J = 3/2) -> 2P (J = 1/2)
where the numbers before the letters are multiplicities (these are term symbols.) likely an application of the zeeman interaction, but I don't understand how.


Thank you.




In a weak magnetic field the $J$ levels are split into $m\_j=\pm1/2$ for $J=1/2$ and $m\_J= 3/2,1/2,-1/2,-3/2$ when $J=3/2$. Transitions between these $6$ levels follow the $\Delta m\_J=0,\pm1$ selection rule. As both states are doublets the $\Delta S=0$ selection rule is also satisfied and the $\Delta L=1$ also between P and D. The splitting between the $J=1/2$ and $J=3/2$ sub-levels (fine structure) is not quit the same so the spectrum should have six lines probably split into three sets of doublets.


 1