Analytical Hartree-Fock gradients for periodic systems

We present the theory of analytical Hartree–Fock gradients for periodic systems as implemented in the code CRYSTAL. We demonstrate how derivatives of the integrals can be computed with the McMurchie–Davidson algorithm. Highly accurate gradients with respect to nuclear coordinates are obtained for systems periodic in 0, 1, 2, or 3 dimensions. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 82: 1–13, 2001