Preface
The rapidly expanding use of ultrafast laser spectroscopic methods to study the
photodynamics of chemical bonds underlines the importance of accurate theoretical
interpretation and modeling of experimental observations. To match this need there
was recent progress in the development and application of computational methods
based on density functional theory (DFT) designed to describe the excited electronic states and the related potential energy surfaces (PESs). These developments
are especially valuable as DFT methods enable one to study the properties of
excited states and to obtain on-the-fly the relevant dynamical parameters of large
molecular and condensed phase species occurring in natural as well as artificial
photoactive systems. As Kohn–Sham DFT is strictly formulated for ground electronic states only [1, 2], excited electronic states are typically accessed through the
use of linear response formalism implemented in time-dependent DFT (TD-DFT)
methodology [3, 4], which currently enjoys a wide popularity among theoretical
photochemists and photophysicists. The widespread use of TD-DFT, however,
revealed certain drawbacks and limitations of the methodology, which are being
constantly addressed through the development of improved computational protocols, new exchange-correlation density functionals, and conceptually new computational approaches. Besides methodological developments in the domain of
linear response TD-DFT, there is growing activity in the field of development of
alternative time-independent DFT methods as well as the methods going beyond
the paradigm of electronic density and exploring the world of (one-electron) density
matrix functionals. Although a number of excellent reviews of TD-DFT formalism
can be found in the literature [5–9], the rate of new developments seems to outpace
the rate of review publishing. This book attempts to fill the gap by providing a
collection of chapters addressing the most recent developments in the realm of DFT
methodology for the excited electronic states written by leading experts in the field.
The opening chapter (p. 1) of the book gives a broad perspective on linear
response TD-DFT and its formal connection to many-body theory. By exploring
the latter, the authors expand on the possibilities to ameliorate some well-known
deficiencies of currently available TD-DFT methodology, especially with regard to
treatment of double (and, in general, multiple) excitations and proper description of
The rapidly expanding use of ultrafast laser spectroscopic methods to study the
photodynamics of chemical bonds underlines the importance of accurate theoretical
interpretation and modeling of experimental observations. To match this need there
was recent progress in the development and application of computational methods
based on density functional theory (DFT) designed to describe the excited electronic states and the related potential energy surfaces (PESs). These developments
are especially valuable as DFT methods enable one to study the properties of
excited states and to obtain on-the-fly the relevant dynamical parameters of large
molecular and condensed phase species occurring in natural as well as artificial
photoactive systems. As Kohn–Sham DFT is strictly formulated for ground electronic states only [1, 2], excited electronic states are typically accessed through the
use of linear response formalism implemented in time-dependent DFT (TD-DFT)
methodology [3, 4], which currently enjoys a wide popularity among theoretical
photochemists and photophysicists. The widespread use of TD-DFT, however,
revealed certain drawbacks and limitations of the methodology, which are being
constantly addressed through the development of improved computational protocols, new exchange-correlation density functionals, and conceptually new computational approaches. Besides methodological developments in the domain of
linear response TD-DFT, there is growing activity in the field of development of
alternative time-independent DFT methods as well as the methods going beyond
the paradigm of electronic density and exploring the world of (one-electron) density
matrix functionals. Although a number of excellent reviews of TD-DFT formalism
can be found in the literature [5–9], the rate of new developments seems to outpace
the rate of review publishing. This book attempts to fill the gap by providing a
collection of chapters addressing the most recent developments in the realm of DFT
methodology for the excited electronic states written by leading experts in the field.
The opening chapter (p. 1) of the book gives a broad perspective on linear
response TD-DFT and its formal connection to many-body theory. By exploring
the latter, the authors expand on the possibilities to ameliorate some well-known
deficiencies of currently available TD-DFT methodology, especially with regard to
treatment of double (and, in general, multiple) excitations and proper description of