  We present extensive new \emph{ab initio} path integral Monte Carlo (PIMC)
results for a variety of structural properties of warm dense hydrogen and
beryllium. To deal with the fermion sign problem -- an exponential
computational bottleneck due to the antisymmetry of the electronic thermal
density matrix -- we employ the recently proposed
[\textit{J.~Chem.~Phys.}~\textbf{157}, 094112 (2022); \textbf{159}, 164113
(2023)] $\xi$-extrapolation method and find excellent agreement with exact
direct PIMC reference data where available. This opens up the intriguing
possibility to study a gamut of properties of light elements and potentially
material mixtures over a substantial part of the warm dense matter regime, with
direct relevance for astrophysics, material science, and inertial confinement
fusion research.
