CP2K

CP2K is a quantum chemistry and solid state physics software package that can perform atomistic simulations of solid state, liquid, molecular, periodic, material, crystal, and biological systems. CP2K provides a general framework for different modeling methods such as DFT using the mixed Gaussian and plane waves approaches GPW and GAPW. Supported theory levels include DFTB, LDA, GGA, MP2, RPA, semi-empirical methods (AM1, PM3, PM6, RM1, MNDO), and classical force fields (AMBER, CHARMM). CP2K can do simulations of molecular dynamics, metadynamics, Monte Carlo, Ehrenfest dynamics, vibrational analysis, core level spectroscopy, energy minimization, and transition state optimization using NEB or dimer method.
CP2K is written in Fortran 2003 and can be run efficiently in parallel using a combination of multi-threading, MPI, and CUDA.

Diffusion
CP2K is freely available under the GPL license. The code is distributed in frequent releases as well as directly available from the developers source repository. There are about 70 downloads per week. There are about 300 peer reviewed publications per year that use the CP2K code. The CP2K web site provides numerous resources for additional information on the code. There are also frequent tutorials and workshops that are dedicated to CP2K.

Scaling
CP2K uses MPI/OpenMP parallelization as well as GPU acceleration. The sparse matrix multiplication library DBCSR has been shown to scale up to thousands of nodes. The wavefunction correlation methods and linear scaling DFT methods that are dominated by DBCSR operations inherit the good scaling. Standard DFT calculations of systems with a few thousand atoms can efficiently use hundreds of nodes.