Axe 3 : Theory

Theory aims at understanding the processes associated with the synthesis and properties of individual or assembled nano-objects, as well as the modeling in a complex environment of the phenomena of interest for applications, in “real” conditions.

A first objective of the theory axis is to understand the processes associated with the synthesis of nanoparticles, the properties of the latter taken individually or on nanostructure assemblies. Theoretical chemistry allows such rationalization, provided that the methods used are adapted to the appropriate scale to describe the object. In addition, the interconnectivity between these methods (hybrid methodologies) and the existence of overlaps (methods covering several time or space scales and scales that can be modeled by several methods) open the way to multiscale modeling approaches adapted to these systems.

They lead us to propose, as a second objective of the theory axis, to provide the keys to understanding the synthesis-structure-properties links existing in inorganic nanostructures. This remains a challenge from the point of view of methodological development, which is similar to the development of a digital twin, adapted to the process examined, either within the framework of the development component or in the implementation component. Such a tool could be calibrated and validated by the possibility of relying on experimental data obtained by the other two axes. The use of AI methodologies will promote this approach to multi-scale integration but also more generally between theory and experience. These models will make it possible to analyze how a property (structural, electronic, energetic or spectroscopic) can be linked to concrete aspects of structure but also to synthesis and assembly processes.

These ambitious developments are made possible by the bringing together, within this GDR, of experts in modeling ranging from quantum mechanics to mesoscopic physics, including classical or coarse-grain molecular dynamics. They will thus be supported by research carried out to respond to the challenges associated with this GDR: nucleation growth coupling, environmental effects, non-equilibrium processes, etc.