frequently applied to account for relativistic effects, the authors review conventional
and unconventional single- and multireference approaches, developed to model the
multireference nature of actinide compounds and their ground- and excited-state
electronic structures, finishing with geminal-based approaches. In addition, concepts of quantum information theory are introduced, providing a qualitative
understanding of complex electronic structures of actinide compounds using the
picture of interacting orbitals.
The set of next four chapters is generally devoted to spectroscopic issues where
the interplay between experiment and theory is frequently indispensable for the
interpretation of the spectra and translates the gained information into chemical
insights. In Chapter “Computational Versus Experimental Spectroscopy for
Transition Metals” Maja Gruden, Wesley R. Browne, Marcel Swart, and Carole
Duboc discuss a variety of examples where different spectroscopy techniques aided
by computations allow to determine intricate and elusive properties, like the oxidation state, spin state, or coordination environment around redox-active metal ions
such as iron, manganese, or nickel.
Marcus Lundberg and Mickaël G. Delcey show in Chapter “Multiconfigurational
Approach to X-ray Spectroscopy of Transition Metal Complexes” how close correlation between theoretical modeling and X-ray experiment allows for the identification of the electronic and geometric structure of transition metal system
through their spectral fingerprint from the core excitation energies. Compared to
ground state calculations, modeling of X-ray spectra is complicated by the presence
of the core hole, which typically leads to multiple open shells and large effects of
spin–orbit coupling. Thus, reliable fingerprinting requires a theoretical model that is
accurate enough, and the authors show that multiconfigurational wave function
approaches, recently extended to model a number of X-ray processes of transition
metal complexes, are suitable for that purpose. Chapter “Assessing Electronically
Excited States of Cobalamins via Absorption Spectroscopy and Time-Dependent
Density Functional Theory” by Megan J. Toda, Pawel M. Kozlowski, and Tadeusz
Andruniów is specifically devoted to one type of systems, B12 chemistry. Due to
the complexity and the size of the cobalamins, the computational analysis is almost
exclusively represented by DFT and time-dependent DFT (TD-DFT) methods; thus,
the proper choice of exchange-correlation functional discussed by authors is of
paramount importance in predicting electronic transitions and simulating the full
spectrum reliably. Chapter “Photodeactivation Channels of Transition Metal
Complexes: A Computational Chemistry Perspective” by Daniel Escudero which
concludes this section deals with the fate of the excited states in a transition metal
compound, deactivating via a plethora of interconnected relaxation processes,
competing with each other and controlled by the subtle interplay of electronic
and geometrical rearrangements. The author provides critical overview of the
state-of-the-art quantum chemical and reaction dynamic methods to study the
photodeactivation dynamics in transition metal compounds and illustrates the progress and challenges in this field with recent examples on a variety of excited states
in photoactive iridium and ruthenium complexes.
Preface
vii
and unconventional single- and multireference approaches, developed to model the
multireference nature of actinide compounds and their ground- and excited-state
electronic structures, finishing with geminal-based approaches. In addition, concepts of quantum information theory are introduced, providing a qualitative
understanding of complex electronic structures of actinide compounds using the
picture of interacting orbitals.
The set of next four chapters is generally devoted to spectroscopic issues where
the interplay between experiment and theory is frequently indispensable for the
interpretation of the spectra and translates the gained information into chemical
insights. In Chapter “Computational Versus Experimental Spectroscopy for
Transition Metals” Maja Gruden, Wesley R. Browne, Marcel Swart, and Carole
Duboc discuss a variety of examples where different spectroscopy techniques aided
by computations allow to determine intricate and elusive properties, like the oxidation state, spin state, or coordination environment around redox-active metal ions
such as iron, manganese, or nickel.
Marcus Lundberg and Mickaël G. Delcey show in Chapter “Multiconfigurational
Approach to X-ray Spectroscopy of Transition Metal Complexes” how close correlation between theoretical modeling and X-ray experiment allows for the identification of the electronic and geometric structure of transition metal system
through their spectral fingerprint from the core excitation energies. Compared to
ground state calculations, modeling of X-ray spectra is complicated by the presence
of the core hole, which typically leads to multiple open shells and large effects of
spin–orbit coupling. Thus, reliable fingerprinting requires a theoretical model that is
accurate enough, and the authors show that multiconfigurational wave function
approaches, recently extended to model a number of X-ray processes of transition
metal complexes, are suitable for that purpose. Chapter “Assessing Electronically
Excited States of Cobalamins via Absorption Spectroscopy and Time-Dependent
Density Functional Theory” by Megan J. Toda, Pawel M. Kozlowski, and Tadeusz
Andruniów is specifically devoted to one type of systems, B12 chemistry. Due to
the complexity and the size of the cobalamins, the computational analysis is almost
exclusively represented by DFT and time-dependent DFT (TD-DFT) methods; thus,
the proper choice of exchange-correlation functional discussed by authors is of
paramount importance in predicting electronic transitions and simulating the full
spectrum reliably. Chapter “Photodeactivation Channels of Transition Metal
Complexes: A Computational Chemistry Perspective” by Daniel Escudero which
concludes this section deals with the fate of the excited states in a transition metal
compound, deactivating via a plethora of interconnected relaxation processes,
competing with each other and controlled by the subtle interplay of electronic
and geometrical rearrangements. The author provides critical overview of the
state-of-the-art quantum chemical and reaction dynamic methods to study the
photodeactivation dynamics in transition metal compounds and illustrates the progress and challenges in this field with recent examples on a variety of excited states
in photoactive iridium and ruthenium complexes.
Preface
vii