  We analyze the scattering of light from dipolar emitters whose disordered
positions exhibit correlations induced by static, long-range dipole-dipole
interactions. The quantum-mechanical position correlations are calculated for
zero temperature bosonic atoms or molecules using variational and diffusion
quantum Monte Carlo methods. For stationary atoms in dense ensembles in the
limit of low light intensity, the simulations yield solutions for the optical
responses to all orders of position correlation functions that involve
electronic ground and excited states. We calculate how coherent and incoherent
scattering, collective linewidths, line shifts, and eigenmodes, and
disorder-induced excitation localization are influenced by the static
interactions and the density. We find that dominantly repulsive static
interactions in strongly confined oblate and prolate traps introduce
short-range ordering among the dipoles which curtails large fluctuations in the
light-mediated resonant dipole-dipole interactions. This typically results in
an increase in coherent reflection and optical depth, accompanied by reduced
incoherent scattering. The presence of static dipolar interactions permits the
highly selective excitation of subradiant eigenmodes in dense clouds. This
effect becomes even more pronounced in a prolate trap, where the resonances
narrow below the natural linewidth. When the static dipolar interactions affect
the optical transition frequencies, the ensemble exhibits inhomogeneous
broadening due to the nonuniformly experienced static dipolar interactions that
suppress cooperative effects, but we argue that, e.g., for Dy atoms such
inhomogeneous broadening is negligible.
