Three mutually related problems concerning the interaction of an electron with an alkaline-earth atom are examined. (i) The scattering problem: the phaseshifts for p-electron scattering by Ca, Sr and Ba are calculated. (ii) The negative ion problem: the wavefunction and the binding energy are obtained for the outer electron in Ca-4s24p, Sr-5s25p and Ba-6s26p ions. (iii) The photodetachment problem: the photodetachment cross sections are calculated for the outer electron in each of these ions. The most intriguing feature of these problems is the strong correlational potential, attracting the electron to the atom due to the large dipole polarizabilities of Ca, Sr and Ba. The calculations are performed by means of the Dyson equation of the many-body theory.
The photodetachment cross sections are calculated for the outer np and nearby ns subshells of the C- 2p3 4S, Si- 3p3 4S and Ge- 4p3 4S negative ions. The prominent interference feature with deep minimum is discovered for the np photodetachment in the vicinity of the ns threshold at omega approximately=6 eV. This structure is due to the strong interaction of the np continuum with the ns to in p shape resonance. This resonance corresponds to the transition of the ns electron to the quasi-bound 'np' state with the width Gamma (1 eV. The shape resonance undergoes rapid decay into the np continuum that is analogous to the super-Coster-Kronig transition. The asymmetry parameter for the np photoelectron angular distribution is calculated, showing abrupt changes in the same energy region. The calculations are performed using the spin-polarized version of the random phase approximation with exchange.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.