Motion picture of a conical intersection

Chemical Physics In most chemical reactions, electrons move earlier and faster than nuclei. It is therefore common to model reactions by using potential energy surfaces that depict nuclear motion in a particular electronic state. However, in certain cases, two such surfaces connect in a conical intersection that mingles ultrafast electronic and nuclear rearrangements. Yang et al. used electron diffraction to obtain time-resolved images of CF3I molecules traversing a conical intersection in the course of photolytic cleavage of the C–I bond (see the Perspective by Fielding). Science , this issue p. [64][1]; see also p. [30][2] [1]: /lookup/doi/10.1126/science.aat0049 [2]: /lookup/doi/10.1126/science.aat6002