eqn

\begin{equation} \frac{\partial }{\partial t}( \psi^{*} \psi ) = \frac{1}{i \hbar} \left( \frac{\hbar^2 \psi \nabla^2 \psi^{*}}{2 m} - \frac{\hbar^2 \psi^{*} \nabla^2 \psi}{2 m} \right) \nonumber \end{equation}