Recommended electron-impact excitation and ionization cross sections for Be I
FNU Dipti, Tapasi Das, klaus Bartschat, I Bray, D Fursa, O Zatsarinny, C Ballance, H-K Chung, Yuri Ralchenko
Analytic fits to the recommended electron-impact excitation and ionization cross sections for Be I are presented. The lowest 19 terms of configurations 2snl (n 4) and 2p2 terms below the first ionization limit are considered. The fits are based on the accurate calculations with the convergent close coupling (CCC) method as well as the B-spline R-matrix (BSR) approach. The fitted cross sections provide rate coefficients that are believed to approximate the original data within 10% with very few exceptions. The oscillator strengths for the dipole-allowed transitions between all the considered states are calculated with the relativistic multi-configuration Dirac-Hartree-Fock (MCDHF) approach and compared with the CCC and BSR results. This comparison shows a very good agreement except for a handful of cases with likely strong cancellations.