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 r s = 75 ( 5 ) and Wigner crystallization (to a body-centered cubic crystal) to occur at r s = 100 ( 20 ) . 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 r s = 50 ( 2 ) to about 100 ; and Wigner crystallization occurs at r s = 106 ( 1 ) .