Quantum Monte Carlo (QMC) methods, which provide an explicit treatment of electron correlation effects, are generally agreed to provide the most accurate quantitative approach for determining the zero-temperature phase diagram of jellium. The first application of the diffusion Monte Carlo method was Ceperley and Alder's famous 1980 calculation of the zero-temperature phase diagram of 3D jellium. They calculated the paramagnetic-ferromagnetic fluid transition to occur at formula_30 and Wigner crystallization (to a body-centered cubic crystal) to occur at formula_31. Subsequent QMC calculations have refined their phase diagram: there is a second-order transition from a paramagnetic fluid state to a partially spin-polarized fluid from formula_32 to about formula_33; and Wigner crystallization occurs at formula_34.