THE F-2(O) RYDBERG SERIES AND LOW-LYING AUTOIONIZING STATES OF AL

By applying a theory which unifies the ab initio treatment of electron ic structure, of electron correlation and of valence-Rydberg-continuum interactions, we calculated hitherto unknown properties of the Al F-2 (o) spectrum. The KL(3s3p)P-3(o) nd states lie above threshold, starti ng with the 3d state at 3.0 eV. They decay by autoionization with rate s of the order of 10(12) s(-1). The higher-lying autoionizing (3s3p)P- 1(o) nd states exhibit a stronger interaction with the 3s(2)nf, epsilo n f channel, resulting in an increase of the sr;all quantum defect of the Rydberg series from its Hartree-Fock value by a factor of 20. Usin g a correlated wavefunction for the D-2 lowest state, the oscillator s trengths for D-2-F-2(o) transitions for low n, for high n and for free -electron energies up to 2.7 eV are computed.