Ralf W. Grosse-Kunstleve wrote:
I.e. the first 99999 serial numbers are represented as usual. The following atoms use a base-36 system (10 digits + 26 letters) with upper-case letters. 43670016 (26*36**4) additional atoms can be numbered this way. If there are more than 43770015 (99999+43670016) atoms, a base-36 system with lower-case letters is used, allowing for 43670016 additional atoms. I.e. in total 87440031 (99999+2*43670016) atoms can be stored and uniquely referenced via CONECT records.
Wow- 86 million atoms, say MW 12 gives 1 gigadalton, divide by avogadro's number gives 1.7 10^-15 g/particle, which with a density of 1 would be a particle about 12 microns in diameter. Should be OK for anything with an asymmetric unit smaller than 120,000 x 120,000 x 120,000 A. With that kind of capacity, it won't be long before people start crystallizing whole bacterial cells. Like for instance 2QJP: Crystal structure of wild type Rhodobacter sphaeroides with stigmatellin and antimycin inhibited http://www.pdb.org/pdb/search/structidSearch.do?structureId=2qjp But when someone needs to do the cryo-EM single-particle structure of C. elegans at atomic resolution, we'll have the same old problem again (unless the solvent content is really high). Ed
