\documentclass[12pt]{article} \usepackage{amssymb,amsmath,amscd,concmath} \pagestyle{empty} \begin{document} \begin{equation*}\frac{H\Psi}{\Psi}=\frac{(-\frac{\nabla^2}{2}+V)\Psi}{\Psi}\end{equation*} \end{document}