When I mentioned about an electron repelling itself I was making a phacetious reference to density functional theory (theory which uses the density to variationally determine the ground state energy) wherein one approach (the most used appraoch when dealing with DFT) you have an approximate...
Remember what your hamiltonian is made of: a kinetic energy as well as a potential energy part. The potential energy component (admittedly the most difficult part to create, especially for polyelectronic systems) is all about attraction and repulsion of electrons and nuclei (using the example of...