Regular article Inclusion of exact exchange for self-interaction corrected H 3 density functional potential energy surface

Abstract

Abstract. The e€ect of the inclusion of the exact exchange into self-interaction corrected generalized gradient approximation density functional theory (GGA-DFT) for the simplest hydrogen abstraction reaction, H + H2 ® H3 ® H2 + H, is presented using a triple-zeta augmented 6-311++G(d,3pd) basis set. The introduction of the self-interaction correction has a considerably larger e€ect on molecular geometry and vibrational frequencies than the inclusion of the exact exchange. We investigate the in¯uence of the selfinteraction error on the shape of the potential energy surface around the transition state of the hydrogen abstraction reaction. The decomposition of the selfinteraction error into correlation and exchange parts shows that the exchange self-interaction error is the main component of the energy barrier error. The best agreements with the experimental barrier height were achieved by self-interaction corrected B3LYP, B-LYP and B3PW functionals with errors of 1.5, 2.9 and 3.0 kcal/mol, respectively. Key words: Hydrogen abstraction reaction barrier ± Self-interaction components ± B3LYP and B3PW functionals ± Self-interaction corrected molecular geometries ± Self-interaction corrected total energies