So, I was reading about the quantum http://en.wikipedia.org/wiki/Rigid_rotor" [Broken] and apparently its solutions are the so-called spherical harmonic functions, which are the solution to the angular portion of Laplace's equation. The way I see it, the rigid rotor Schroedinger equation is not the angular part of Laplace's equation (because of that E[tex]\Psi[/tex]part of the rigid rotor equation). Am I right? Am I missing something? Am I completely wrong? Maybe these functions are solutions to both equations? 2. Relevant equations [tex]\Delta[/tex][tex]\Psi[/tex]=0 (Laplace's equation) (-h-bar2/2[tex]\mu[/tex])[tex]\Delta[/tex][tex]\Psi[/tex]=E[tex]\Psi[/tex] 1. The problem statement, all variables and given/known data Errrr... I'm have a hard time writing these equations here, it's just worth mentioning that it's not 2 to the power of mu, but 2 times mu.