1. Griffiths problems 4.2, 4.4, and 4.5
2. Schematically construct a 3-D Hamiltonian for an electron confined to a 4x2x2 torus, i.e. periodic along the direction w/ 4 segments.
3. Calculate the energy eigenvalues of the isotropic 3-d harmonic oscillator using finite differences, and indicate the degeneracies of the 3 lowest energies. Plot the iso-density surfaces of the seven eigenstates with the lowest energy.