Time-dependent natural orbitals and occupation numbers
Fritz-Haber-Institut der Max-Planck-Gesellschaft - Faradayweg 4-6, D-14195 Berlin, Germany, EU
2 Max-Planck-Institut für Mikrostrukturphysik - Weinberg 2, D-06120 Halle, Germany, EU
3 European Theoretical Spectroscopy Facility (ETSF)
Accepted: 1 October 2010
Using the equations of motion for the occupation numbers of natural spin orbitals we show that adiabatic extensions of common functionals employed in ground-state reduced-density-matrix-functional theory have the shortcoming of leading to occupation numbers independent of time. We illustrate the exact time-dependence of the natural spin orbitals and occupation numbers for two strongly nonlinear cases, namely electron-ion scattering and atoms in strong laser fields. In the latter case, we observe strong variations of the occupation numbers in time.
PACS: 31.15.E- – Density-functional theory / 31.70.Hq – Time-dependent phenomena: excitation and relaxation processes, and reaction rates / 32.80.Qk – Coherent control of atomic interactions with photons
© EPLA, 2010