1. 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)

2. spatial part
spin part
Two electrons are located in 2 different MO shells: both singlet and triplet states exist
Two electrons are located in same MO shell and same spatial orbital: only singlet state
3. Two electrons are located in same MO shell but different spatial orbitals:
e.g. O2, most stable configuration
Symmetric spatial part
L = l1+l2 = 0
Antisymmetric spin part = singlet 
Antisym. spatial part
Symmetric spin part = triplet 

3. S+ or S- ? f1

5. e.g.

6. Franck-Condon factor

7. e.g: ortho-H2 (I=1, Ns=3)
para-H2 (I=0, Na=1)