[ General Glossary, Quantum Glossary, Atomic Glossary ]
The OIII] Line

This is a so-called semi-forbidden transition (Electric Dipole transition, but Delta S is not equal to zero)

Energy (eV) [Wavelength (nm)]	Ion	Lower Config Upper Config	Notes
6.4956291 [190.8734]	C III	2s2 1S0 2s(2S)2p 3Po1	Aki = 1.14x102 s-1 fki = 1.87x10-7

Remember C III is twice ionized carbon (ie C⁺²), thus there are 4 electrons in the system. In the ground-state, this ion has two electrons in the K-shell (ie 1s²), and two electrons in the L-shell (ie 2s²). Now of course there are other states available within the L-shell (specifically the six levels associated with the 2p configuration, ie with L=1).

From the configuration it can be seen that the transition is actually a semi-forbidden electric dipole intercombination transition between the ground-state of the C III ion and the J=1 member of the ³P^o term.

There are other possible transitions associated with the 2p subshell. See CIII energy levels.