CP2K is a freely available quantum chemistry and solid state physics software package that can perform atomistic simulations of solid state, liquid, molecular, periodic, material, crystal, and biological systems.
Ab-initio electronic structure theory methods using the QUICKSTEP module
Density-Functional Theory (DFT) energies and forces,
Hartree-Fock (HF) energies and forces, Moeller-Plesset 2nd order perturbation theory (MP2) energies and forces, Random Phase Approximation (RPA) energies, Gas phase or Periodic boundary conditions (PBC), and more.
Mixed quantum-classical (QM/MM) simulations
Real-space multigrid approach for the evaluation of the Coulomb interactions between the QM and the MM part, Linear-scaling electrostatic coupling treating of periodic boundary conditions, Adaptive QM/MM