The left mouse button is used for atom identification. Move the cursor to the center of any atom, and touch the left mouse button. All atoms fairly close to the cursor will be displayed in the text window as well as the title bar. Note: it is difficult to pick an atom when drawn as a sphere because the pick area is very small compared to the usual sphere size. It is usually helpful to switch to the vector drawing before picking. The center mouse button has its default action of window moving. The right mouse button brings up the pop-up menu.