Cleanthes A. Nicolaides – författare

This book, the first volume of a two-part monograph, is centered on key background fundamentals and results, and on the  description of the State- and Property-Specific Approach (SPSA) to the construction and implementation of efficacious methods for the quantitative solution of various types of time-independent or time-dependent problems in Quantum Chemistry and in Atomic, Molecular, Optical, and Chemical Physics. By going beyond the standard many-electron problem for ground states, the discussion mainly addresses the key aspects of the SPSA methodology for the calculation of wavefunctions of excited discrete states and of resonance (autoionizing) states that are tailored to each property or phenomenon of interest. In particular, the SPSA uses state-specific function spaces and practicable computational methods that allow insightful and economic descriptions of excited-state electronic structures and the systematic calculation of the interplay between electronic structures (including electron correlations) on the one hand and spectra and dynamics on the other. The Hamiltonians (nonrelativistic or relativistic) are either field-free or include weak or strong electromagnetic fields that may be static, or periodic, or pulsed. The arguments and commentary in both volumes of the monograph are supported by a plethora of numerical examples and by comparisons with experiment.

This book, the first volume of a two-part monograph, is centered on key background fundamentals and results, and on the  description of the State- and Property-Specific Approach (SPSA) to the construction and implementation of efficacious methods for the quantitative solution of various types of time-independent or time-dependent problems in Quantum Chemistry and in Atomic, Molecular, Optical, and Chemical Physics. By going beyond the standard many-electron problem for ground states, the discussion mainly addresses the key aspects of the SPSA methodology for the calculation of wavefunctions of excited discrete states and of resonance (autoionizing) states that are tailored to each property or phenomenon of interest. In particular, the SPSA uses state-specific function spaces and practicable computational methods that allow insightful and economic descriptions of excited-state electronic structures and the systematic calculation of the interplay between electronic structures (including electron correlations) on the one hand and spectra and dynamics on the other. The Hamiltonians (nonrelativistic or relativistic) are either field-free or include weak or strong electromagnetic fields that may be static, or periodic, or pulsed. The arguments and commentary in both volumes of the monograph are supported by a plethora of numerical examples and by comparisons with experiment.

This book, the second volume of a two-part monograph, consists mainly of State- and Property-Specific Approach (SPSA) formulations for the efficient calculation of properties and of phenomena in N-electron atoms and molecules. Its bulk deals with nonperturbative solutions of the many-electron, time-independent or time-dependent Schrӧdinger equations using Hermitian or non-Hermitian (complex energy) constructions that account consistently for the contribution of both the discrete and the multichannel continuous spectra. It covers a wide range of applications, including the prediction of spectra and properties of excited discrete and resonance (autoionizing, autodissociating) states, the construction of diabatic molecular states and their use in real systems for solving problems of reaction and of molecular bonding, multiphoton ionization and dissociation (including tunneling), field-induced partial and total energy shifts and decay rates, properties of negative ions in ground or excited open-shell states, ultrafast electron dynamics and electron rearrangements on femtosecond and attosecond timescales, and other topics.

It is undoubtedly true that much of the progress in the quant~m theory of matter is due to the remarkable success of the independent particle model (IPM)--especially in describing ground states. However, the accurate experimental results of the last 10 years or so, on a variety of spectroscopic phenomena and chemical processes which involve the Excited State, and the related failure of the IPM to reproduce accurately--in many cases, even qualitatively--the observed data, have sent to theorists a clear message: There is need to create and/or apply general and useful approaches to the many-electron problem of the excited state which go beyond the IPM, treat electron correlation and relativity and explain or predict all relevant physical or chemical information with consistent accuracy. This book contains articles devoted mainly to some of the most important new developments in Quantum Chemistry concerning the theoretical foundations and the computational implementation of many-body approaches to the quantitative and detailed under­ standing of the electronic excited states of atoms, molecules and solids. Furthermore, it contains experimental and pheno­ menological articles on Photoelectron and Auger spectroscopy, Lifetime measurements and Organic Photochemistry. In combination or individually, these articles constitute a good description of some current theoretical and experimental work on the electronic structure and spectroscopy of atoms, molecules, polymers, surfaces, metal oxides and amorphous solids.