The Institut de Chimie Physique (ICP, Institute for Physical Chemistry) is a research unit which was built upon the integration of several teams of physical and analytical chemists within the Orsay perimeter of the Université Paris-Saclay ranging from its creation under the name Laboratoire de Chimie Physique in 2000 to its current organization under the name Institut de Chimie Physique in 2020.

The ICP is structured in four scientific groups (CAPRI, CPSysBio, TEMiC, TheoSim) and two shared services. The scientific groups carry the activities in research, doctoral and intern training, and collaborations with exterior researchers. The shared services bring technical support (Instrumentation service) and support for daily activities of the scientific groups (General services: administrative tasks, logistics, infrastructure, computer support).

Within the scientific groups are attached the research platforms, led by researchers and supported by dedicated technical staff. Their aim is to open world or national-scale unique facilities (both equipment and expertise) for access to external users. These platforms include two instruments based on electron accelerators, one dedicated to time-resolved radiolysis and photolysis (ELYSE) and the other to the generation of infra-red laser beams (CLIO). These platforms are members of European (FELs of Europe) and national (Infranalytics, EMIR&A) networks. The MUSIICS and CLIO/SMAS platforms are supported since 2021 in the priority equipment of the ORIGINS and LUMA PEPR programs.