1. Better approximations:

3. (+/-) Term symbol: 2S+1L(g/u)
In the absence of spin-orbit coupling, the projection L of electronic angular momentum
L on molecular axis is conserved. L
(+/-)
Term symbol: 2S+1L(g/u) L

4. Limiting cases of united atoms and separated atoms

6. N2
Lowest-energy configuration
First two excited configurations
All shells fully occupied (N2): 1Sg+
(...) : Pg state (multiplicity, see later)
(...) : is similar to hole
 states are like those for , i.e.
(see table)