2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/209553Successful modern generalized gradient approximations (GGA's) are biased toward atomic energies. Restoration of the first-principles gradient expansion for exchange over a wide range of density gradients eliminates this bias. We introduce PBEsol, a revised Perdew-Burke-Ernzerhof GGA that improves equilibrium properties of densely-packed solids and their surfaces.4 pages, 2 figuresMaterials Sciencetext