Finally, the states obtained with EA-TDDFT are orthogonal amongst themselves but nonorthogonal to the n-electron ground state. While the excitation energies can be computed with minimal (0.01 eV) error by directly subtracting the n-electron ground state energy from the energy of each excited state (ω r = E r -E n SCF ), the transition dipole moments are far more sensitive to nonorthogonality and must be computed by projecting out the overlap with the ground state,