Dynamic (hyper)polarizability density analysis based on virtual excitation processes: visualization of the dynamic electron fluctuatability of systems under time-dependent external electric fields

A novel method for the analysis of dynamic (hyper)polarizabilities of systems in the presence of arbitrary time-dependent external electric fields is developed. By using a new concept the ‘dynamic (hyper)polarizability density’, we visualize the a ability of dynamic electron fluctuation (electron fluctuatability) of systems with relaxation processes under external electric fields with arbitrary intensities, frequencies and shape of amplitudes. The (hyper)polarizability density is partitioned into that for each virtual excitation process by the numerical Liouville approach.