  We propose a Jastrow factor for electron-electron correlations that
interpolates between the radial symmetry of the Coulomb interaction at short
inter-particle distance and the space-group symmetry of the simulation cell at
large separation. The proposed Jastrow factor captures comparable levels of the
correlation energy to current formalisms, is 40% quicker to evaluate, and
offers benefits in ease of use, as we demonstrate in quantum Monte Carlo
simulations.
