Cover Image, Volume 40, Issue 9

Si‐Dian Li and his group from Shanxi University, in their article on page 966, propose the concept of fluxional bonds in planar B 19 −, tubular Ta@B 20 −, and cage‐like B 39 − as an extension of the classic localized bonds and delocalized bonds in chemistry. Fluxional bonds form, break, and rotate constantly in boron nanoclusters in a concerted mechanism like the rolling balls in a mechanical bearing. They may exist in other systems beyond boron and have important applications in molecular dynamics and reaction mechanisms. Background art courtesy of Vecteezy.com . (doi: 10.1002/jcc.25728 )