The bridge function of hard spheres by direct inversion of computer simulation data

The bridge function of the hard sphere fluid has been calculated from our new highly accurate Monte Carlo and molecular dynamics simulation data on the radial distribution function using the (inverted) Ornstein-Zernike equation. Both the systematic errors (finite size, grid size, tail) and statistical errors are analysed in detail and ways to suppress them are proposed. Uncertainties in the resulting values of B(r) are about 0.001. In contrast with many previous findings the bridge function is both positive and negative.