  Electrostatic multipole interactions generate long-range Rydberg-Rydberg
macrodimer. We calculate the adiabatic potentials of cesium $(nD_{J})_2$
Rydberg macrodimers for principal quantum numbers $n$ ranging from 56 to 62,
for $J=3/2$ and $5/2$, and for the allowed values of the conserved sum of the
atomic angular-momentum components along the internuclear axis, $M$. For most
combinations $(n, M, J)$ exactly one binding potential exists, which should
give rise to Rydberg macrodimer states. We study the dependence of the
adiabatic potentials on the size of the two-body basis sets used in the
calculation, and on the maximal order, $q_{max}$, of the multipole terms
included in the calculation. We determine the binding energies and lengths of
the binding adiabatic potentials, and investigate their scaling behaviors as a
function of the effective principal quantum number; these parameters are
relevant to experimental preparation of Rydberg-atom macrodimers. Avoided
crossings between adiabatic potentials affect the well shapes and the scaling
behaviors differently in two distinct domains in $n$. We discuss an
experimental scheme for preparing $(nD_J)_2$ Rydberg-atom macrodimers using
two-color double-resonant photoassociation.
