A configuration interaction calculation of the potential energy surface of Li₃

Abstract

Large-scale configuration interaction calculations of the potential energy surface of Li₃ are described. The major prediction which emerges is that triangular configurations are more stable than linear ones, with the ²B₂ and ²A₁ states having different equilibrium geometries but essentially the same energies. It is found that the most stable linear configuration is symmetric, unlike the prediction of restricted Hartree-Fock calculations. A fit of our calculated surface to a semi-empirical LEPS function is presented.