Oops I am outdated: Axel just emailed me that he describes an improved coordinate estimate beyond the Rayleigh criterion in his recent paper
Schroder GF, Levitt M, & Brunger AT (2010) Super-resolution biomolecular crystallography with low-resolution data. Nature 464(7292), 1218-1222. For the deformable elastic network (DEN) refinement, see his ref 14 Schroder GF, Brunger AT, & Levitt M (2007) Combining efficient conformational sampling with a deformable elastic network model facilitates structure refinement at low resolution. Structure 15(12), 1630-1641. BR
