[ccp4bb]: Low Resolution Heavy Metal Derivatives

[Noinaj]

Hi,   I have previously collected a native dataset at 2.4 angstroms (a few months ago).  I recently used some old crystals for heavy metal soaks using MeHgCl and was only able to collect to around 7 angstroms.  The crystals seem to have 'died' over time, since I also tried some that weren't soaked for comparison and they didn't diffract past 7 angstroms either.  We were able to observe a fluorescent signal from the crystals indicating the presence of Hg, but my question is, is 7 angstroms enough resolution to find the Hg sites with confidence?    I intended to use this in combination with a molecular replacement solution, that I feel is very good (Z-score is 31 in Phaser), but the crystal packing has significant overlap in some regions.  I am currently soaking new crystals with MeHgCl for better resolution, and trying to grow SelenoMet crystals, so I don't want to waste my time if the data that I have now just isn't worth the effort.   Thanks for any and all help in advance.        Cheers, Nick