CROSS SECTIONS CALCULATIONS FOR ELECTRON--OXYGEN SCATTERING USING THE POLARIZED ORBITAL CLOSE COUPLING THEORY.

The formulation given by Feautrier et al. (1971) for transitions induced by electron impact among ground state terms of atoms with one configuration npq is used with a slight modification by taking into account the orthogonality of the free wavefunction to the bound npq orbitals. A system of coupled integro differential equations, obtained from a modified close coupling expansion by including long range pseudo states, is solved numerically for electron incident on oxygen in the threshold region. The present results agree very closely with experiment. Independently of the evident astrophysical interest of these results (especially the excitation cross sections of the forbidden lines), the generalizations of such calculations to other systems with the same type of configuration is straightforward with this automatic code. The multichannel photodetachment cross sections of O- by dipole length and velocity formulae are also reported and discussed.