Could you provide me a selection rule?

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Discussion Overview

The discussion centers around the selection rules for electric dipole transitions, specifically in the context of neutral Argon as referenced in the NIST Atomic Spectra Database. Participants explore how to properly apply these rules, particularly for L-S coupling, and seek clarification on the rigorous rules mentioned in the selection rule table.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses difficulty in understanding how to use the selection rules for electric dipole transitions, focusing on L-S coupling for Argon.
  • Another participant outlines the selection rules, noting that transitions must adhere to specific criteria, including changes in total angular momentum (J), magnetic quantum number (Mj), orbital quantum number (l), spin (S), and total orbital quantum number (L).
  • There is mention of forbidden transitions that may occur under certain conditions, such as particle collisions, which do not follow the selection rules.
  • A participant seeks clarification on the definitions of total orbital quantum number (L), total magnetic quantum number (S), and individual orbital quantum number (l), as well as literature references for the selection rules.
  • Textbook references are provided by another participant, suggesting specific sources where selection rules are discussed in detail.

Areas of Agreement / Disagreement

Participants generally agree on the importance of selection rules for determining transition possibilities, but there is uncertainty regarding the application of rigorous rules and the definitions of quantum numbers. The discussion remains unresolved regarding the best approach to utilize the selection rules effectively.

Contextual Notes

Participants express uncertainty about the definitions of quantum numbers and the applicability of rigorous rules, indicating a need for further clarification and exploration of the topic.

goodphy
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Hello.

When I accessed to selection rule page in Wikipedia, I have a difficulty of how to use rules listed there.

I'm now only concering electric dipole transition so column (E1) in the table there will be my only interests. Since I need to know whether transition is possible or not between energy states of neutral Argon listed in NIST Atomic Spectra Database, I thought I only take rules for L-S coupling as NIST data is in term symbol so Argon is L-S coupling.

However, what about "Rigorous rules" in the table there? Is it also what should I take?

Please help me so that I can use the table in proper way:)
 
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I write this hoping it might in someway be helpful to you,but don't take it for granted look into these things yourself as I have actually forgotten most of the topic.
A transition between levels is possible only if it follows all these selection rules listed here(not sure what the intermediate coupling they have given there is)
i.e. for the transition to be possible it should follow
1)delta(J)=0,+/-1 , note transition from J=0 to J=0 is not allowed.
2)delta Mj=0 ,+/-1, Mj=0 to Mj=0 is not allowed
3)delta(l)=+/-1
4)delta(S)=0
5)delta(L)=0, +/-1, L=0 to L=0 transition not allowed
Also there can be transitions not following these conditions(forbidden transitions),they happen mainly when there is collisions among particles.
 
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Daymare said:
I write this hoping it might in someway be helpful to you,but don't take it for granted look into these things yourself as I have actually forgotten most of the topic.
A transition between levels is possible only if it follows all these selection rules listed here(not sure what the intermediate coupling they have given there is)
i.e. for the transition to be possible it should follow
1)delta(J)=0,+/-1 , note transition from J=0 to J=0 is not allowed.
2)delta Mj=0 ,+/-1, Mj=0 to Mj=0 is not allowed
3)delta(l)=+/-1
4)delta(S)=0
5)delta(L)=0, +/-1, L=0 to L=0 transition not allowed
Also there can be transitions not following these conditions(forbidden transitions),they happen mainly when there is collisions among particles.

Hello. Thanks to give me comment.

Is L and S are total orbital quantum number (azimuthal quantum number) and total magnetic quantum number respectively while l is orbital quantum number for each electron state? And can you tell me what literature or article is used for suggesting these rules? I think I need very strong confidence in selection rule as it will be useful tool for my furhter research:)
 
Sure,here are the textbooks I followed when I had course on spectroscopy.
1)C.N Banwell Fundamentals of molecular spectrocopy
2)Modern spectroscopy,Michael J Hollas
3)Basic Atomic and Molecular Spectroscopy,Michael J Hollas
4)Molecular Quantum mechanics,Peter Atkins and Ronald Friedman
You will see what I have told you about selection rules on page 48 of option (3).If you want to go little more into the details its good to look into option 4.
 
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