Concepts and Practical Aspects of Computational Chemistry

Within the last decade, computational organic chemistry is frequently used to determine the energies of ground states and transition states and, consequently, activation energies of reactions. Computational studies are vitally important for a modern analysis of reaction mechanisms. This chapter first briefly looks at hard- and software requirements, before it presents typical computational methods and basis sets in organic chemistry. It then focuses on frequent applications in organic chemistry and their notation in publications. The chapter uses a tutorial reaction to see how computational chemistry can help to understand chemical reactions. The general aim of any computational investigation is the use of a computer program to obtain some output from a given input. Molecular mechanics is among the simplest computational methods. Within a model chemistry used to analyze a given problem in organic chemistry, the user has to select both a computational method and a basis set.