For academic researchers, postdocs, graduate and undergraduate students, reports the most updated and accurate theoretical techniques to treat electronic excited states. From methods to deal with stationary calculations through time-dependent simulations of molecular systems, this book serves as a guide for beginners in the field and knowledge seekers alike. Taking into account the most recent theory developments and representative applications, it also covers the often-overlooked gap between theoretical and computational chemistry. An excellent reference for both researchers and students, provides essential knowledge on quantum chemistry, an in-depth overview of the latest developments, and theoretical techniques around the properties and nonadiabatic dynamics of chemical systems. Readers will learn: ●      Essential theoretical techniques to describe the properties and dynamics of chemical systems ●      Electronic Structure methods for stationary calculations ●      Methods for electronic excited states from both a quantum chemical and time-dependent point of view ●      A breakdown of the most recent developments in the past 30 years For those searching for a better understanding of excited states as they relate to chemistry, biochemistry, industrial chemistry, and beyond, provides a solid education in the necessary foundations and important theories of excited states in photochemistry and ultrafast phenomena.