VARIATIONAL MONTE-CARLO STUDY OF THE PARTIALLY POLARIZED ELECTRON-GAS

The variational Monte Carlo (VMC) method, using Jastrow-Slater (JS) wa ve functions, is used to study the partially polarized interacting ele ctron gas for densities spanning the range encountered in bulk metals. We concentrate on a spin polarization zeta=0.42 which allows direct c omparison of polarized and unpolarized states for a fixed total number of electrons in the simulation supercell. The radial distribution fun ctions g(++)(r), g(__)(r), and g(+_)(r) are given particular attention and compared with a model developed by Perdew and Wang (PW) that sati sfies known constraints. At high density the agreement with the PW mod el is good. At the lower densities (electron-gas parameter r(s)=4-8) t here are differences that can be roughly characterized as the PW model giving a somewhat more extended exchange-correlation hole than the VM C calculations. These discrepancies could be due to limitations either of the PW model or of the JS wave functions used here. Both the VMC a nd PW results are contrasted with the Hartree-Fock result for parallel spins.