1. Principles of molecular simulation

Although often used interchangeably, the concepts of molecular modeling and molecular simulation need to be differentiated. To do so, we'll consider the definitions given by Le Petit Robert for the words modeling and simulation. Modeling is "putting a complex phenomenon into equations in order to predict its equations. Especially: the establishment of a mathematical model that can be understood by a computer to describe and reproduce a natural object". As for the term simulation, we'll take the definition dating from the mid-twentieth century: "representation of the behavior of physical systems (by digital computers, etc.) by simulating real quantities with appropriate signals". We therefore need to build the models that will best represent, i.e. simulate, the systems which, in the case of this article, are mainly the amorphous phase of linear polymers. A sub-section will focus on melting...