chemical bond dissociation. The dressed TD-DFT approach and its current and
potential capabilities are discussed in detail. An entirely different approach to
describing excited states in the context of DFT is taken in the following two
chapters, which expand on the use of time-independent methodologies. The
constricted-variational DFT method, presented in the second chapter (p. 61), has
the potential to outperform the currently available linear response TD-DFT when
describing excitations in large conjugated systems or charge transfer excitations,
both of which are notoriously difficult for the standard linear response TD-DFT
formalism. A practically accessible implementation of ensemble DFT formalism,
presented in the next chapter (p. 97), holds great promise for theoretical modeling
of non-adiabatic relaxation processes of excited electronic states, relevant to photochemistry and photovoltaics, and provides proper description of real and avoided
crossings between the ground and excited electronic states of large molecular
species. To complement these new developments, the fourth chapter (p. 125) gives
a wide perspective on the general background and practical aspects of a novel
quantum theoretical approach to the ground and excited states of electronic systems
– density matrix functional theory (DMFT). Although a younger methodology than
DFT, DMFT has the potential to overtake its counterpart once practically affordable
functionals of the one-body density matrix become available.
Methodological aspects of the theoretical description of excited electronic states
in the condensed phase and open quantum systems in the framework of TD-DFT are
amply discussed in the fifth and sixth chapters of the book. On p. 185 Ullrich and
Yang give a comprehensive survey of currently available exchange-correlation
kernels of TD-DFT, analyze their shortcomings, and outline possible remedies for
the description of excitonic states in condensed phase systems. A comprehensive
and pedagogical review of theoretical approaches, such as complex scaling and
open boundary conditions, for the description of time-dependent phenomena in
open quantum systems, especially with regard to resonance states photoemission
spectroscopy, is given in the chapter by Rubio et al. on p. 219. A contemporary and
encyclopedic presentation of various approaches for theoretical modeling of
nonlinear core and valence X-ray spectra is presented by Mukamel et al. on
p. 273 in the seventh chapter of the book. In this chapter the use of DFT/TD-DFT
methods to address the demands of nonlinear X-ray spectroscopy measurements are
analyzed in depth and the prospect of their use are outlined.
Practical aspects of using TD-DFT for computational description of molecular
electronic spectroscopy are reviewed in the chapter by Jacquemin and Adamo on
p. 347. Special emphasis was put on going beyond the vertical excitation approximation in TD-DFT and including vibronic effects for realistic description of 0–0
transition energies in real-life molecular systems. The use of TD-DFT for computational modeling of absorption spectroscopy, emission properties, and ultrafast
intersystem crossing processes in transition metal complexes is surveyed by Daniel
(p. 377) in Chap. 8, where special attention is paid to the inclusion of spin-orbit and
vibronic effects in TD-DFT computations. The ability of the DFT/TD-DFT framework to provide a proper description of dynamical effects on the spectroscopic and
photochemical properties of molecular species is analyzed in the chapters by
viii
Preface
potential capabilities are discussed in detail. An entirely different approach to
describing excited states in the context of DFT is taken in the following two
chapters, which expand on the use of time-independent methodologies. The
constricted-variational DFT method, presented in the second chapter (p. 61), has
the potential to outperform the currently available linear response TD-DFT when
describing excitations in large conjugated systems or charge transfer excitations,
both of which are notoriously difficult for the standard linear response TD-DFT
formalism. A practically accessible implementation of ensemble DFT formalism,
presented in the next chapter (p. 97), holds great promise for theoretical modeling
of non-adiabatic relaxation processes of excited electronic states, relevant to photochemistry and photovoltaics, and provides proper description of real and avoided
crossings between the ground and excited electronic states of large molecular
species. To complement these new developments, the fourth chapter (p. 125) gives
a wide perspective on the general background and practical aspects of a novel
quantum theoretical approach to the ground and excited states of electronic systems
– density matrix functional theory (DMFT). Although a younger methodology than
DFT, DMFT has the potential to overtake its counterpart once practically affordable
functionals of the one-body density matrix become available.
Methodological aspects of the theoretical description of excited electronic states
in the condensed phase and open quantum systems in the framework of TD-DFT are
amply discussed in the fifth and sixth chapters of the book. On p. 185 Ullrich and
Yang give a comprehensive survey of currently available exchange-correlation
kernels of TD-DFT, analyze their shortcomings, and outline possible remedies for
the description of excitonic states in condensed phase systems. A comprehensive
and pedagogical review of theoretical approaches, such as complex scaling and
open boundary conditions, for the description of time-dependent phenomena in
open quantum systems, especially with regard to resonance states photoemission
spectroscopy, is given in the chapter by Rubio et al. on p. 219. A contemporary and
encyclopedic presentation of various approaches for theoretical modeling of
nonlinear core and valence X-ray spectra is presented by Mukamel et al. on
p. 273 in the seventh chapter of the book. In this chapter the use of DFT/TD-DFT
methods to address the demands of nonlinear X-ray spectroscopy measurements are
analyzed in depth and the prospect of their use are outlined.
Practical aspects of using TD-DFT for computational description of molecular
electronic spectroscopy are reviewed in the chapter by Jacquemin and Adamo on
p. 347. Special emphasis was put on going beyond the vertical excitation approximation in TD-DFT and including vibronic effects for realistic description of 0–0
transition energies in real-life molecular systems. The use of TD-DFT for computational modeling of absorption spectroscopy, emission properties, and ultrafast
intersystem crossing processes in transition metal complexes is surveyed by Daniel
(p. 377) in Chap. 8, where special attention is paid to the inclusion of spin-orbit and
vibronic effects in TD-DFT computations. The ability of the DFT/TD-DFT framework to provide a proper description of dynamical effects on the spectroscopic and
photochemical properties of molecular species is analyzed in the chapters by
viii
Preface