Planning the next generation of density functional codes

Real-space pseudopotential density functional theory has proven to be an efficient avenue for computing the properties of matter in many different states and geometries, including liquids, wires, slabs and clusters with and without spin polarization. Fully self-consistent solutions have been routinely obtained for systems with thousands of atoms. However, there are still systems where quantum mechanical accuracy is desired, but scalability proves to be a hindrance, such as large biological molecules or complex interfaces. We will present an overview of our work on algorithms for this problem, which has taken the route of improved scalability by spectrum slicing in the eigensolver, {\it i.e.}, the construction of a ``parallel'' eigensolver. We will also discuss how accurate forces can be obtained for ``coarse grids.''