  Evolutionary calculations for stars in close binary systems are in high
demand to obtain better constraints on gravitational wave source progenitors,
understand transient events from stellar interactions, and more. Modern
one-dimensional stellar codes make use of the Roche lobe radius $R_{\rm L}$
concept in order to treat stars in binary systems. If the stellar companion is
approaching its $R_{\rm L}$, mass transfer treatment is initiated. However, the
effective acceleration also affects the evolution of a star in a close binary
system. This is different from the gravity inside a single star, whether that
single star is rotating or not. Here, we present numerically obtained tables of
properties of stars in a binary system as a function of the effective
potential: volume-equivalent radii of the equipotential surfaces, effective
accelerations and the inverse effective accelerations averaged over the same
equipotential surfaces, and the properties of the L1 plane cross-sections. The
tables are obtained for binaries where the ratios of the primary star mass to
the companion star mass are from $10^{-6}$ to $10^5$ and include equipotential
surfaces up to the star's outer Lagrangian point. We describe the numerical
methods used to obtain these quantities and report how we verified the
numerical results. We also describe and verify the method to obtain the
effective acceleration for non-point mass distributions. We supply a sample
code showing how to use our tables to get the average effective accelerations
in one-dimensional stellar codes.
