The visual effect above is awful, sorry.
1. Sufficient and neccesary conditions for normal Zeeman triplet is:
The total number of electrons is even, and the electrons form the state with S=0, 2S+1=1.
2. As to the famous sodium doublet, the 589.6nm line will split into four lines, with frequency difference 2/3 Lorentz unit (LU), 3/4 LU, 2/3 LU, respectively; the 589.0nm line splits into six ones, with identical frequency difference of 2/3 LU. No line exists at the initial location any more.
Comments:
1. Sodium Doublet: 589.6nm: 2P_(3/2) ----->2S_(1/2), 589.0nm: 2P_(1/2) ----->2S_(1/2).
2. Transition Rule: \Delta m = +1, 0, -1.
589.0nm: 2P_(1/2) ----->2S_(1/2), m, mg
---|----------------------------------------------------- 3/2, 2
---|---------|----|-------------------------------------- 1/2, 2/3
---|---------|----|---------|----|---------------------- -1/2, -2/3
---|---------|----|---------|----|----------|----------- -3/2, -2
1 1 1 1 1 1
1 1 1 1 1 1
1 1 1 1 1 1
---|---------|----|---------|----|----------|----------- 1/2, 1
------------------|--------------|----------|----------- -1/2, -1
589.6nm: 2P_(1/2) ----->2S_(1/2), m, mg
---|---------------------------------------------------- 1/2, 2/3
---|---|-----------------|----|------------------------- -1/2, -2/3
1 1 1 1
1 1 1 1
1 1 1 1
---|---|-----------------|----|-------------------------- 1/2, 1
-------|----------------------|-------------------------- -1/2, -1
where $g$ above is Lande g fractor, and for effectively mono-electron atoms, such as 1H, 3Li, 11Na, 19K, 29Cu, 47Ag, 79Au,
3 1 S * (S+1) -- L * (L+1)
g = --- + --- (---------------------------------)
2 2 J * (J+1)