Interplay of strong chemical bonds and the repulsive Coulomb force in the metastable states of triply ionized homonuclear molecules: A theoretical study of N3+2 and O3+2

摘要

We have studied metastable electronic states of trication molecules for N2n3+ and O2n3+ using the internallyncontracted multireference configuration interaction method with single and double excitations (icMRCISD).nThe metastable ground state for O2n3+ and metastable excited state for N2n3+ were obtained with the barriers ofnapproximately 1.5 and 13.0 kcal/mol, respectively, although those metastable states were not found in previousncalculations. The analysis on occupation numbers of natural orbitals demonstrates that the two metastable statesnare formed owing to the balance between the reduction of cationic Coulomb repulsion and the weakening of thenchemical bonds. We have proposed to measure these metastable states by short-wavelength free-electron lasersn(sFELs) that have the potential to produce excited states of multiply charged molecules.