The principal focus of this volume is to illustrate the level of accuracy currently achievable by ab initio quantum chemical calculations. While new developments in theory are discussed to some extent, the major emphasis is on a comparison of calculated properties with experiment. This focus is similar to the one taken in a book, Comparison of Ab Initio Quantum Chemistry with Experiment for Small Molecules, edited by Rodney Bartlett (Reidel, 1984). However, the phenomenal improvement in both theoretical methods and computer architecture have made it possible to obtain accurate results for rather large molecular systems. This is perhaps best illustrated in this volume by the chapter entitled `Spectroscopy of Large Organic Molecules' by Bjorn Roos and coworkers. For example, the electronic spectra of the nucleic acid base monomer structures shown on the front cover have been obtained using a fully correlated ab initio study.
For researchers, teachers and students in chemistry and physics.

Exact Quantum Chemistry by Monte Carlo Methods; J.B. Anderson. Achieving Chemical Accuracy with Coupled-Cluster Theory; T.J. Lee, G.E. Scuseria. Magnetic Hyperfine Coupling Constants in Free Radicals; D.M. Chipman. Calculation of Accurate Bond Energies, Electron Affinities, and Ionization Energies; L.A. Curtiss, K. Raghavachari. Accurate Theoretical Studies of Small Elemental Clusters; K. Raghavachari, L.A. Curtiss. Electronic Spectroscopy of Diatomic Molecules; H. Partridge, S.R. Langhoff, C.W. Bauschlichter Jr. Theoretical Spectroscopy of Small Molecules: Ab Initio Investigations of Vibronic Structure, Spin-Orbit Splittings and Magnetic Hyperfine Effects in the Electronic Spectra of Triatomic Molecules; M. Peric, B. Engels, S.D. Peyerimhoff. Theoretical Studies of the Electronic Spectra of Organic Molecules; B.O. Roos, M. Fulscher, P.-A. Malmqvist, M. Merchan, L. Serrano-Andres. Index.