SIESTA (Spanish Initiative for Electronic Simulations with Thousands of Atoms) is a density functional package that can be used to perform electronic structure calculations and ab initio molecular dynamics simulations of molecules and solids. The workshop will be taken by SIESTA-developers Professor Emilio Artacho (University of Cambridge), Professor Julian Gale (Curtin University of Technology) and Dr Alberto GarcÃa (Institut de Ciencia de Materials de Barcelona).