$$ W \, \psi ~=~ - \frac{\hbar^2}{2m} \, \left[ \frac{1}{r^2} \frac{\partial}{\partial r} \left( r^2 \, \frac{\partial \psi}{\partial r} \right) ~+~ \frac{1}{r^2 \, \sin(\theta)} \frac{\partial}{\partial \theta} \left( \sin(\theta) \, \frac{\partial \psi}{\partial \theta} \right) ~+~ \frac{1}{r^2 \, \sin^2(\theta)} \frac{\partial^2 \psi}{\partial \varphi^2} \right] ~+~ W_{\text{pot}} \, \psi $$
