Molecular nanomagnets (also known as single-molecule magnets or SMMs) provide a tantalizing glimpse of the future possibilities for high-density data storage, with the potential to provide storage densities 25,000 times better than current technology.

Their well-defined molecular size and spin structure has led to observation of quantum effects such as tunneling of the magnetization, and could lead to applications in the field of quantum computing. These materials need to be well characterized by single crystal X-ray diffraction to allow any magnetic properties that are observed to be investigated and modeled. Unfortunately, these materials often produce small crystals that push the limits of ordinary laboratory diffractometers, usually requiring a more powerful X-ray source such as a rotating anode or a synchrotron. The  RAPID II has allowed a different approach, with datasets being collected for longer exposure times for anything that is too weak to be collected on a standard diffractometer. Examples of these compounds are shown below.

A mixed-valence Co₇ structure (left), a mixed-valence Mn₈ structure (middle) and a mixed-metal Fe₈Cu₂ structure (right)