1. “Forbidden Transitions”
Selection Rules
Harry Kroto 2004

2. Electron Configuration O2+ 1s2 2s2 2p2 like carbon Terms 1S 1D 3P
Harry Kroto 2004

3. Electron Configuration O2+ 1s2 2s2 2p2 like carbon Terms 1S 1D 3P 1S0
Harry Kroto 2004

4. Electron Configuration O2+ 1s2 2s2 2p2 like carbon Terms 1S 1D 3P 1S0
Harry Kroto 2004

5. Intensity - Magnetic Dipole / Electric Dipole
Selection Rules
Electric Dipole
L = 1 S = 0
S  S T  T Sl T
Magnetic Dipole
S =  S  T
Intensity - Magnetic Dipole / Electric Dipole
= 1/2 = 1/ = x 10-5
 1/( ) (+ one for the pot) according to Eddington
Electric Quadrupole 1/108
 J =  2
Harry Kroto 2004

6. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0 p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

7. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0 p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

8. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
10s p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

9. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
10s p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

10. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
104 s
10s p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

11. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
104 s
10s p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

12. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
104 s
10s
2 s p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

13. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
104 s
10s
2 s p2
1D2
3P2
3P1
3P0
Harry Kroto 2004

14. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
104 s
10s
2 s p2
1D2
50s
3P2
3P1
3P0
Harry Kroto 2004

15. 1S0
104 s
10s
2 s p2
1D2
50s
3P2
3P1
3P0
Harry Kroto 2004

16. 1S0 p2 1D2 3P2 3P1 3P0 Electric Dipole L = 1 S = 0 S ↔S T ↔ T
Magnetic Dipole 5 x 10-5
S =  S ↔ T
Electric Quadrupole 1/108
 J =  2
1S0
104 s
10s
2 s p2
1D2
50s
160s
3P2
3P1
3P0
Harry Kroto 2004

17. Hot gas cloud –the famous Orion Nebulae
At the centre is the Trapezium Cluster of very hot new stars
Harry Kroto 2004

18. Harry Kroto 2004