# Hydrogen excitation (griffiths 9.1)

1. Jan 16, 2005

### wizzart

I'm trying to solve problem 9.1 from griffiths book on quantum mechanics. I've written down the hydrogen wavefunctions for all combinations allowed of n, l and m. Now according to griffiths (and my memory) only one excitation is actually allowed between n=1 and n=2. This would minimize the amount of integration. Problem is, I can't find out wich wave functions have no business here. Any help would be welcome, spec. if you could give the correct set of n,l,m and motivation (so don't start TEX-ing in all the wave functions, there in the book).

2. Jan 16, 2005

### da_willem

As you are integrating over all of space all integrands that are odd in z vanish. Furthermore integrands containing $e^{+/- i \phi}$ vanish for more or less the same reason.

3. Jan 16, 2005

### wizzart

tx

slowly figuring it out...Thanks Willem, see you on Friday

4. Jan 16, 2005

### da_willem

:tongue2: :surprised Wizzart...aka?!

5. Jan 17, 2005

### wizzart

:rofl: Rutger, 4th year student, doing lotsa 3rd year stuff. Usually talking with people like Egge, Erwin or Martijn. Check the picture on my website, probably more useful than vague descriptions... :rofl:

6. Jan 17, 2005

### da_willem

Aha, Rutger... Nice site, and cartoons! I especially liked the one about Steve Vai . Good luck studying QM...