POTENTIAL-ENERGY CURVES OF GROUND AND EXCITED-STATES OF TETRA HALOMETHANES AND THE NEGATIVE-IONS

A large scale multireference configuration interaction study (involving up to 2.3 million configurations) of potential energy curves for ground and excited states for dissociative electron attachment are presented for CCl4/CCl4-, CBr4/CBr4-, and CI4/CI4- systems. The spin-orbit coupling in CI4/CI4- is also calculated using the relativistic configuration interaction approach. The results agree reasonably well with the available experimental data for electron affinities, giving a confidence in the overall quality of potential surfaces. The study leads to a better understanding of the reaction CX(4)+e-->[CX(4)](-)-->CX(3)+X(-), which is believed to be an important step in biological processes involving halocarbons.