Short-range correlation in the uniform electron gas: Extended Overhauser model

We use the two-electron wavefunctions (geminals) and the simple screened Coulomb potential proposed by Overhauser [Can. J. Phys. 73, 683 (1995)] to compute the pair-distribution function for a uniform electron gas. We find excellent agreement with Quantum Monte Carlo simulations in the short-range region, for a wide range of electron densities. We are thus able to estimate the value of the second-order coefficient of the small interelectronic-distance expansion of the pair-distribution function. The results are generalized to the partially polarized gas.