  We present a robust strategy to numerically sample the Coulomb potential in
reciprocal space for periodic Born-von Karman cells of general shape. Our
approach tackles two common issues of plane-wave based implementations of
Coulomb integrals under periodic boundary conditions, the treatment of the
singularity at the Brillouin-zone center, as well as quadrature errors, which
can cause severe convergence problems in anisotropic cells, necessary for the
calculation of low-dimensional systems. We apply our strategy to the
Hartree-Fock (HF) and coupled cluster (CC) theory and discuss the consequences
of different sampling strategies on the different theories. We show that
sampling the Coulomb potential via the widely used probe-charge Ewald method is
unsuitable for CC calculations in anisotropic cells. To demonstrate the
applicability of our developed approach, we study two representative,
low-dimensional use cases: the infinite carbon chain, for which we report the
first periodic CCSD(T) potential energy surface, as well as a surface slab of
lithium hydride, for which we demonstrate the impact of different sampling
strategies for calculating surface energies. We find that our Coulomb sampling
strategy serves as a vital solution, addressing the critical need for improved
accuracy in plane-wave based CC calculations for low-dimensional systems.
