[blaisem]

I am asked to calculate how much energy it would take to break an O₂(X³Σ^-) molecule into two O(³P) atoms.

I get that O(³P) refers to the Russel-Saunders Term symbol with spin multiplicity of 3 and total orbital quantum number of L = 1 ( or P).

I am not familiar with the oxygen diatomic notation.  Is this simply a normal O₂ molecule? Regardless, what is this notation called?

Thanks!

[Corribus]

They are still term symbols, and the meanings of the various elements are essentially the same, but they are for molecules rather than atoms. Molecular term symbols use Greek letters (Σ, Π, Δ, ...) in place of the standard S, P, D, F, G... that you see in atomic term symbols, but the meaning is identical. The character in front of the term symbols refers to the number of the state of identical multiplicity in increasing energy according to an overall energy level diagram. The X is a special case the designates the ground molecular state.

http://en.wikipedia.org/wiki/Molecular_term_symbol

[blaisem]

Thanks as always Corribus.