Basis set and electron correlation effects on the electron affinities of first row atoms.

In this work, the electron affinities of boron, carbon, oxygen and fluorine atoms have been evaluated by many-body perturbation calculations through complete fourth order using several large basis sets. The convergence of the perturbation series has been evaluated carefully by means of modified coupled cluster methods. Large basis sets and electron correlation effects involving higher excitations are found to be important in the accurate calculation of electron affinities.