The external field with resonant frequency can be used to drive the system significantly away from its reference state (the Hartree-Fock state in the current study). With the application of a resonant field to a two-level system, the population of the S 0 and S 1 states should undergo Rabi oscillation, inverting at a frequency directly proportional to the field amplitude and the transition dipole moment between the two states, calculated as Ω Rabi = |µ x,S0→S1 | × E max,x . Previous studies on twolevel systems have shown that Rabi cycle-like oscillatory behavior of the electron density propagated using RT-TDHF can deviate significantly from the exact electron dynamics. The difference in electron dynamics is attributed to detuning of the resonant frequency due to the dependence of the XC potential on the instantaneous electron density. This effect can be significant depending on the fraction of electron density rearranged with respect to the total electron density. Understanding the potential errors of a given methodology in modeling a system in the presence of a resonant field is important for simulating many varieties of pump-probe and nonlinear spectroscopy.