Pseudopotentials for cold atoms P.O. Bugnion, G.J. Conduit and R.J. Needs An accurate computational description of ultracold atoms interacting with effective repulsive interactions has proved elusive. Previous computational work has either used a truly repulsive potential (most often, a hard sphere), which fails to recover the very short-range nature of the interactions, or the excited states of an attractive potential. In this presentation, we propose a new pseudopotential, inspired by those used in electronic structure work. This potential is carefully tuned to recover the correct scattering length and effective range for a broad range of atomic energies, and does not have an undesirable bound state. This will greatly facilitate quantum Monte-Carlo and exact diagonalization simulations of cold atoms.