I'm having problem with griffith QM problem 4.43:(adsbygoogle = window.adsbygoogle || []).push({});

Construct the spatial wave function for hydrogen in the state n = 3, l =2, m = 1. Express your answer as a function of r, [tex]\theta[/tex], [tex]\phi[/tex], and a (the Bohr radius) only.

My prof. gave hints about radial wave function, but I have no idea how to construct spherical harmonics from scratch. The book only shows spherical harmonic are eigenfunctions of [tex]L^2[/tex] and [tex]L_z[/tex], not how you can generate them with [tex]L_{\pm}[/tex] operators. So is there a way to generate spherical harmonics with operators similar to harmonic oscillator operator method? I guess more specifically, is there a way to get spherical harmonics for [tex]Y_{l=2}^{m=0}[/tex]? I know I can apply [tex]L_{+}[/tex] to get [tex]Y_{l=2}^{m=1}[/tex].

edit: nevermind, looks like Griffith made generating spherical harmonics into problem 4.22 as oppose to showing how to do it. that was very tricky of my professor to sneak another problem into homework.

edit2: i'm having problems with 4.22...

denoting spherical harmonics as [tex]Y_{l}^{m}(\theta,\phi)=f(\theta)g(\phi)[/tex], solve for [tex]g(\phi)[/tex] first.

[tex]L_{z}Y_{l}^{l}=\hbar l Y_{l}^{l}[/tex]

[tex]g(\phi)=e^{i l \phi}[/tex] as expected.

now for [tex]f(\theta)[/tex]

[tex]L_{+}Y_{l}^{l}=0[/tex]

where [tex]L_{+}=\hbar e^{i \phi}(\partial_{\theta}+i \cot \theta \partial_{\phi})[/tex]

solving this I get

[tex]\ln f(\theta) = \frac{l}{\hbar}e^{i \phi} \ln \sin \theta[/tex]

which doesn't look right... it's an exponential of an exponetial... any clues as to what I did wrong?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Constructing spatial wave function of hydrogen

**Physics Forums | Science Articles, Homework Help, Discussion**