Tests of a density functional with Laplacian terms: activation barriers and bond-stretching energies

A recently proposed exchange-correlation functional that goes beyond the conventional gradient approximation by including the contributions from the Laplacian of the density is applied to investigate molecular potential surfaces. Activation barriers in simple chemical reactions are reported as well as bond-stretching energies in diatomic molecules. The results are of similar quality to those from the B3LYP hybrid functional, without using any admixture of Hartree–Fock exchange or parametrization against molecular data.