Alright, I'm back with yet another question... So the prof was explaining that the energy in an infinite cubical well is E((h2∏2)/2ma2))(nx2+ny2+nz2) Which is all well and good, and he gave us the example of: ψ1,2,1 = E = 6((h2∏2)/2ma2)) And with little explanation mixed it up once switching one of the 1's with the 2. After some searching through my book I found out that this is the first energy level or E1, and has 3-fold degeneracy. Simply enough, E2 is ψ1,2,2 with 3 -fold degeneracy also.. But after looking online, I find that E3 is not ψ2,2,2. How do you derive/find out what to use for the quantum numbers? As I found out, ψ2,2,2 is E4. Is there a pattern? Or a formula? Any help is appreciated.