About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Paper
Configuration-interaction study of atoms. II. Electron affinities of B, C, N, O, and F
Abstract
Extensive configuration-interaction calculations have been carried out to determine electron affinities of the first-row atoms, B to F. Calculated electron affinities in eV with the observed values in parentheses are 0.15, 1.11(1.25), -0.52, 1.13(1.461), and 3.12(3.448), for B, C, N, O, and F, respectively. Our best estimates, based on an empirical extrapolation which makes use of the known C, O, and F affinities, for B and N electron affinities are 0.24 and -0.19 eV, respectively. Detailed analysis of the results in terms of contributions from various classes of configurations shows that the K-shell and K L-intershell correlation-energy contributions to these electron affinities are negligibly small, and that about 15% of the total correlation contribution comes from the triple and higher electron-excitation configurations. Symmetry-adapted pair-correlation calculations have been carried out for O, O-, F, and F- to study convergence patterns for the correlation energy and electron affinity with respect to the orbital basis used to construct the configurations. Such pair-correlation calculations are known to overcompute the correlation energy. The excess energies, which correspond to pair-pair interaction energies neglected in the pair-correlation calculations, were roughly constant over a range of orbital basis sizes, with magnitudes about twice the energy contributions from the configurations of triple and higher excitations omitted in the pair-correlation calculations. Accordingly, this approximation should overestimate the electron affinity if a complete orbital basis is used. © 1974 The American Physical Society.