Octopus is a scientific program aimed at the 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.

For optimal execution performance Octopus 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.