1. Quantum or ab initio calculations

There are many methods of quantum computation, known as ab initio, available in various freeware and commercial packages. The aim of this section is to give a brief overview of the main methods available. ab initio and the meaning of their names and abbreviations, then focus on the methods that will be used to predict thermochemical properties and the COSMO approach. We won't go into the mathematical details, which can be particularly burdensome, and the reader is referred to some excellent books and articles on the subject