  We propose a simple analytic representation of the correlation energy for the
two-dimensional electron gas, as a function of the density and the spin
polarization. This new parametrization includes most of the known high- and
low- density limits and fits our new fixed-node diffusion Monte Carlo
simulations, performed for a wide range of electron densities and
spin-polarization states. In this way we provide a reliable local-spin-density
energy functional for two-dimensional systems. The corresponding correlation
potential is discussed and compared with previous models.

Strongly Correlated Electrons