Analytical Hartree-Fock gradients with respect to the cell parameter:   systems periodic in one and two dimensions
  Analytical 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. 
K. Doll, R. Dovesi, R. Orlando