ACCURATE CALCULATION OF THE ELECTRON-AFFINITIES OF THE GROUP-13 ATOMS

Using a form of multireference single and double configuration-interaction method as CIPSI, we have tested the ability to obtain accurate values of the electron affinity for non-first-row elements by computing the electron affinity of the group-13 atoms Al, Ga, In, and Tl using pseudopotentials to describe the core electrons, and an extended basis set for the valence electrons. Our results show that it is possible to obtain precise values of the electron affinities of these atoms using the CIPSI method (Al=0.45, Ga=0.29, In=0.38, and Tl=0.27 eV), and that the error induced by the use of pseudopotentials in the CIPSI electron afinities is very small.