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Singlet exciton fission (SF), the formation of two triplet excitons from one singlet exciton, involves electronic, nuclear, and spin degrees of freedom as well as their couplings. Despite almost 60 years of research on this process, a complete microscopic understanding is still missing. One important open question concerns the role of nuclear motion in SF. In this perspective, recent results on the exciton dynamics are related to the structural dynamics of single‐crystal pentacene and how they provide insights into that open question is shown. To probe the electronic dynamics, orbital‐resolved measurements of the electronic structure are carried out using time‐ and angle‐resolved photoemission spectroscopy. With femtosecond electron diffraction and with ab initio computations, the complementary nuclear dynamics is tracked. The results from both techniques are summarized, and how they relate to each other is discussed. Then, remaining open questions are outlined and potential routes are identified to tackle them, hopefully guiding future studies. [ABSTRACT FROM AUTHOR]

4D scanning transmission electron microscopy (4D‐STEM) is a powerful method for characterizing electron‐transparent samples with down to sub‐Ångstrom spatial resolution. 4D‐STEM can reveal local crystallinity, orientation, grain size, strain, and many more sample properties by rastering a convergent electron beam over a sample area and acquiring a transmission diffraction pattern (DP) at each scan position. These patterns are rich in information about the atomic structure of the probed volume, making this technique a potent tool to characterize even inhomogeneous samples. 4D‐STEM can also be used in scanning electron microscopes (SEMs) by placing an electron‐sensitive camera below the sample. 4D‐STEM‐in‐SEMs is ideally suited to characterize 2D materials and 2D‐like van der Waals heterostructures (vdWH) due to their inherent thickness of a few nanometers. The lower accelerating voltage of SEMs leads to strong scattering even from monolayers. The large field of view and down to sub‐nm spatial resolution of SEMs are ideal to map properties of the different constituents of 2D‐like vdWH by probing their combined sample volume. A unique 4D‐STEM‐in‐SEM system is applied to reveal the single crystallinity of MoS2 exfoliated with gold‐mediation as well as the crystal orientation and coverage of both components of a C60/MoS2 vdWH are determined. [ABSTRACT FROM AUTHOR]