# Nomenclature of This State?

I've read this in a book

It says the state having three parallel spin is called triplet state . But as far as I know it is determined by "2S+1", from this it comes out to be 4 . Then how it is "Triplet (3) " ?

• You are correct in that if S is the total spin then $2S+1$ gives the spin multiplicity. As you note in the example $2(3/2)+1 = 4$, a quartet not triplet. – porphyrin Feb 14 '17 at 11:36