Nonequilibrium gas dynamics and molecular simulation The book is divided into two parts based on the overall goals with the first part focusing on fundamental considerations and the second part dedicated to describing computer simulation methods. The first section covers three different areas: (1) kinetic theory (2) quantum mechanics and (3) statistical mechanics. Important results from these three areas are then brought together to allow analysis of nonequilibrium processes in a gas based on molecular level considerations. Chapter 1 covers kinetic theory in which the basic idea is to develop techniques to relate the properties and behavior of particles representing atoms and molecules to the fluid mechanical aspects of a gas at the macroscopic level. This requires us to provide a basic definition by what is meant by a particle and how these particles interact with one another through the mechanism of inter molecular collisions. This leads us into a discussion of modeling of macroscopic molecular transport processes such as viscosity and thermal conductivity that represents one of the first key successes of kinetic theory. We will find that kinetic theory relies on the use of statistical analysis techniques such as probability density functions due to the very large volumes of information involved in tracking the behavior of every single particle in a real gas flow