Electron affinities of 1s22s2p 3Po and 1s22p23P of beryllium

The energies of 1s22s2p24P and 1s22p34So of the beryllium anion are calculated by the methods of full core plus correlation (FCPC) and restricted variation. The relativistic corrections are calculated with first-order perturbation theory. This is an application of FCPC to a five-electron atomic system. The energies obtained are much lower than previously expected. Combined with the most accurate theoretical and experimental data, the electron affinities of beryllium 1s22s2p 3Po and 1s22p23P are predicted to be 289.1(10) and 295.0(7) meV, respectively. The former is considerably larger than the recent measurement of 261(10) meV. The transition wavelength of 1s22s2p24P-1s22p34So is predicted to be at 2653.70(68) A, compared to the experimental observation at 2653.01(9) A. The oscillator strength and the radiative lifetime are also calculated