Conversion of bound states to resonances with changing internuclear distance in molecular anions

Abstract

The complex self-consistent field (CSCF) method has been used to compute the complex potential-energy curves of the lowest 2Σ u+ autodetaching resonance state of F2- and the 2Πg resonance state of N 2-. The calculated width of the 2Π g resonance of N2- as a function of internuclear distance is in excellent agreement with the results of previous calculations by other methods. The SCF energies of the anion and the neutral molecule in these examples cross at an internuclear distance different from that at which the SCF energy of the anion becomes complex. We find this to be a general feature of the SCF description of shape resonance states. Correlation effects appear to be of critical importance in determining the behavior of the resonance states in the crossing region. © 1983 American Institute of Physics.