Kinetic Energy of Electrons: The motion of all electrons in the system, Kinetic Energy of Nuclei: The motion of the atomic nuclei (often simplified using the Born-Oppenheimer approximation), Electron-Nucleus Attraction: The attractive Coulomb force binding electrons to the nuclei, Electron-Electron Repulsion: The repulsive Coulomb force between electrons, Nucleus-Nucleus Repulsion: The repulsive Coulomb force between nuclei.