Molden

Molden is a general molecular and electronic structure processing program.

Major features

 * Reads output from the ab initio packages GAMESS (US) and Gaussian and from semi-empirical packages such as MOPAC, and supports a number of other formats.
 * Displays molecular orbitals or electron density as contour plots or 3D grid plots and output to a number of graphical formats.
 * Animates reaction paths and molecular vibrations.
 * A powerful Z-matrix editor.