Abstract
Excitation energies and probabilities for M1 and E2 transitions within the 2p4 ground-state configuration of 17 species in the O I isoelectronic sequence have been calculated using configuration interaction wavefunctions in the computer program CIV3. Relativistic corrections were included in the Breit-Pauli approximation. Correlation effects within and outside the n=2 complex were taken into account. Results are compared with other work. In the case of oxygen, the value of 0.776 s for the lifetime of the 1S0 state agrees well with the experimental value of 0.76 s. For excitation energies in elements up to Z=28, the authors tend to obtain better agreement with measured values than other theoretical work.