This book serves as an introduction to the capabilities of and procedures for this variety of computational chemistry. It is designed to teach you how to use electronic structure modeling to investigate the chemical phenomena of interest to you. This work was developed using the Gaussian series of computational chemistry programs for all of its specific examples and exercises (specifically Gaussian 94), Other program(s) could be substituted, provided that the necessary features and capabilities were available.
Gaussian is capable of predicting many properties of molecules and reactions, including the following:
♦ Molecular energies and structures
♦ Energies and structures of transition states
♦ Bond and reaction energies
♦ Molecular orbitals
♦ Multipole moments
♦ Atomic charges and electrostatic potentials
♦ Vibrational frequencies 4- IR and Raman spectra
♦ NMR properties
♦ Polarizabilities and hyperpolarizabilities
♦ Thermochemical properties
♦ Reaction pathways
Computations can be carried out on systems in the gas phase or in solution, and in their ground state or in an excited state. Gaussian can serve as a powerful tool for exploring areas of chemical interest like substituent effects, reaction mechanisms, potential energy surfaces, and excitation energies.

This work is structured as a study guide, and it employs a hands-on approach to teaching you how to use electronic structure theory to investigate chemical systems. It is suitable for either individual, self-paced study or classroom use. Naturally, not every section will be relevant to all readers. Accordingly, chapters are designed to be as self-contained as possible; you should focus on those parts which address your research needs and interests.
This book begins with a Gaussian Quick Start tutorial designed to help new Gaussian users begin using the program right away. The remainder of the work is divided into three main parts:
♦ Part 1, Essential Concepts & Techniques, introduces computational chemistry and the principal sorts of predictions which can be made using electronic structure theory. It presents both the underlying theoretical and philosophical approach to electronic structure calculations taken by this book and the fundamental procedures and techniques for performing them.
♦ Part 2, Model Chemistries, provides an in-depth examination of the accuracy, scope of applicability and other characteristics and trade-offs of all of the major wdl-defined electronic structure models. It also gives some general recommendations for selecting the best model for investigating a particular problem.
♦ Part 3, Applications, discusses electronic structure calculations in the context of real-life research situations, focusing on how it can be used to illuminate a variety of chemical problems.