Sudden Rearrangements in Intermediate Molecular Systems

Intensity oscillations are observed in the quasimolecular $K$ x-ray spectrum emitted in high-energy ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$-${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ collisions. The oscillating structure is shown, theoretically, to reflect the existence of a two-step mechanism for the production of molecular-orbital $K$ x rays in which sudden rearrangements of molecular-orbital populations are produced by vibrations between atomic and molecular orbitals of $K$-hole states during the interpenetration of the electronic clouds.