Self-isomerization of nearly planar superatoms formed by actinide embedded gold clusters.

First-principles calculations show a self-isomerization process of the nearly planar superatom, in which the maximum energy difference between different extreme points is below 0.1 eV and a crossing between singlet and triplet states is also involved. Further UV-Vis spectra reveal a correlation between the spectra and structures caused by self-isomerization.