I have used Chimerax for proteins, and it is indeed wonderful. However, now I would like to use it to view output from the Gaussian16 "computational chemistry" program, and I am at a loss. I believe the "volume" command is what I need, but I have a LOT of trouble understanding the terminology of the user documentation for the "volume" command. Perhaps someone can be very specific and guide me in the particular procedure described below (or tell me Chimerax does not do such a thing). I have a Gaussian16 cube file for electron density. (This is electron density on grid points. Chimerax can read this file.) I would like to make a contour plot - say contours in the xy plane at z = 0. I would like to specify the number of contours. I would like to know the distance (in au units) of any point on a particular contour from the origin (x=y=z=0) or even from some arbitrary point in space. I would like some sort of legend indicating the density value of each contour. How can I set this up? It would also be nice to be able to specify any plane. Thanks very much Steve