  Molecular dynamics simulation and recent theory are used to examine density
correlations in semidilute solutions of highly charged, intrinsically flexible
and hydrophilic polyelectrolytes in low salt. Quantitative comparison with no
adjustable parameters is made with recent scattering and osmometry experiments.
Agreement is found for the polymer-polymer structure factor at intermediate
wavevectors q with varying chain charge fraction f. Theory is also in agreement
with simulation and experiment for the osmotic pressure, but not with q -> 0
extrapolations of scattering data that show anomalously large intensities at
low q.
