  In this work, we consider the particle-hole random phase approximation
(phRPA), an approximation to the correlation energy in electronic structure,
and show that the phRPA energy of the H2 molecule correctly dissociates. That
is, as the hydrogen atoms are pulled apart, the phRPA energy of the system
converges to twice the phRPA energy of a single hydrogen atom. Despite the
simplicity of the H2 system, the correct dissociation of H2 is known to be a
difficult problem for density functional approximations. As part of our result,
we prove that the phRPA correlation energy is well-defined.
