2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106575Analytical Hartree-Fock gradients with respect to the cell parameter have been implemented in the electronic structure code CRYSTAL, for the case of one and two-dimensional periodicity. As in most molecular codes, Gaussian type orbitals are used to express the wavefunction. Examples demonstrate that the gradients have a good accuracy.to appear in Theor Chem AccComputational PhysicsChemical Physicstext