.CUBE File Extension
What is a CUBE file?
Gaussian cube format created by the cubegen and cubman programs included with the Gaussian distribution; stores volumetric properties, which are the X-, Y-, and Z-coordinates that are mapped on to a 3D grid associated to a molecular system; may also contain the number of atoms and the number of voxels along the the axes.
Gaussian is an electronic structure program used for computational chemistry. The application uses the ".cube" and ".cub" extensions to save data in the Cube format.