Ground- and lowest excited-state MRDCI potential-energy surfaces for the collinear Li+HF reaction

Abstract

The collinear potential energy surfaces for the ground and lowest excited state of the doublet LiFH system and the evolution of the saddle point with the collision angle for the reaction Li+HF have been determined using a multiple reference single and double excitations configuration-interaction (MRDCI) method and an extended GTO basis set. A diabatic state analysis is made to identify and categorize the two lower eigensolutions, obtaining that the two lower adiabatic states correspond to an avoided crossing between the two lower diabatic states. The height of the collinear saddle point is found to be about 58 kJ/mol above the reactants (versus 85 kJ/mol corresponding to previous results).