  The lowest-order low-energy constants $\Sigma$ and $F$ of chiral pertubation
theory can be extracted from lattice data using methods based on the
equivalence of random matrix theory (RMT) and QCD in the epsilon regime. We
discuss how the choice of the lattice geometry affects such methods. In
particular, we show how to minimize systematic deviations from RMT by an
optimal choice of the lattice geometry in the case of two light quark flavors.
We illustrate our findings by determining $\Sigma$ and $F$ from lattice
configurations with two dynamical overlap fermions generated by JLQCD, using
two different lattice geometries.
