Octopus software free download for DFT calculations in chemistry ab initio virtual experimentation on a hopefully ever-increasing range of system types. Electrons are described quantum-mechanically within density-functional theory (DFT), in its time-dependent form (TDDFT) when doing simulations in time. Nuclei are described classically as point particles. Electron-nucleus interaction is described within the pseudopotential approximation.
Octopus For optimal execution performance is parallelized using MPI and OpenMP and can scale to tens of thousands of processors. It also has support for graphical processing units (GPUs) through OpenCL and CUDA.