[...]... most of any applied computational chemistry paper in the literature Those seeking more depth and details, particularly more derivations and a fuller mathematical treatment, should consult any of three outstanding texts: Essentials of Computational Chemistry by Computational Organic Chemistry By Steven M Bachrach Copyright # 2007 John Wiley & Sons, Inc 1 2 QUANTUM MECHANICS FOR ORGANIC CHEMISTRY Cramer,1... example, the cc-pVDZ basis set for carbon is double-zeta in the valence space and includes a single set of d functions, and the cc-pVTZ basis set is triple-zeta in the valence space and has two sets of d functions and a set of f functions The addition of diffuse functions to the correlation-consistent basis sets is designated with the prefix aug-, as in aug-cc-pVDZ 12 QUANTUM MECHANICS FOR ORGANIC CHEMISTRY. .. of Gaussian-70,9 the first full-featured quantum chemistry computer package that was used by a broad range of theorists and nontheorists So, in this sense, computational quantum chemistry is really only some four decades old The application of quantum mechanics to organic chemistry dates back to ¨ Huckel’s p-electron model of the 1930s.10 – 12 Approximate quantum mechanical treatments for organic molecules... Gaussian-type orbital (GTO) 10 QUANTUM MECHANICS FOR ORGANIC CHEMISTRY As most of chemistry focuses on the action of the valence electrons, Pople developed the split-valence basis sets,7,8 single zeta in the core and double zeta in the valence region A double-zeta split-valence basis set for carbon has three s basis functions and two p basis functions for a total of nine functions, a triple-zeta split... chapters present case studies where computational chemistry has been instrumental in elucidating solutions to organic chemistry problems Each chapter deals with a set of related topics Chapter 2 discusses some fundamental organic concepts like aromaticity and acidity Chapter 3 presents pericyclic reactions Chapter 4 details some chemistry of radicals and carbenes The chemistry of anions is the topic of... chemists One must of course recognize that not all of the calculations indicated in Figure P.1 are focused on organic problems Perhaps a better indicator of the increasing importance of computational methods for organic chemists is the number of articles published in the Journal of Organic Chemistry and Organic Letters that include the words “ab initio,” “DFT,” or “density functional theory” in their title... Orbital Theory New York: Wiley-Interscience, 1986 14 Dewar, M J S., A Semiempirical Life Washington, DC: ACS Publications, 1990 15 Cramer, C J Essential of Computational Chemistry: Theories and Models New York: John Wiley & Sons, 2002 16 Jensen, F., Introduction to Computational Chemistry Chichester, England: John Wiley & Sons, 1999 17 Szabo, A and Ostlund, N S., Modern Quantum Chemistry: Introduction to... discipline has made to the broader chemical community towards our understanding of organic chemistry We begin with a brief and mathematically light-handed treatment of the fundamentals of quantum mechanics necessary to describe organic molecules This presentation is meant to acquaint those unfamiliar with the field of computational chemistry with a general understanding of the major methods, concepts, and acronyms... I aim to demonstrate the major impact that computational methods have had upon the current understanding of organic chemistry I will Figure P.1 Number of citations per year to DFT found in SciFinder (open diamonds) or to Gaussian found in Web of Science (filled squares) PREFACE xv Figure P.2 Number of articles per year in Journal of Organic Chemistry and Organic Letters making reference to “ab initio,”... semi-empirical methods For example, Michael Dewar’s influence on the development of theoretical underpinnings of organic chemistry is certainly underplayed in this book14 because results from MOPAC and its descedants are largely not discussed However, taking a view with an eye towards the future, the principal advantage of the semi-empirical methods over ab initio methods is ever-diminishing Semi-empirical .