Metastable innershell molecular state (MIMS) III: The universal binding energy and bond length of the homonucleus K-shell MIMS

This paper reports the discovery of a universal Z2-dependency of the binding energy of the homonucleus K-shell MIMS (K-MIMS: Metastable Innershell Molecular State bound by K-shell electrons), which has been established by analyzing extensive existing experimental data over several decades. An intuitive analytical theory on the K-MIMS has been developed for the homologous molecules to the He2⁎ excimer, which elucidates the universal Z-dependent behavior of the K-MIMS. The theory predicts a 1/Z-dependency of the K-MIMS bond length, which is in agreement with the quasimolecule sizes estimated from the x-ray generation cross-sections in H-like Bi82+ and U91+ impact on Au solids.