A database can have several definitions of unique for anything - a structure database can have this, too. If you have a chemical compound which can form 10 different tautomers, you can represent the compound by 10 chemical structures (it is still the same compound, though). So, if you define uniqueness on basis of chemical compound, you have one db entry and this one entry has a single (tatuomer-sensitive) InChI covering 10 chemical structures; if you define uniqueness on basis of tautomers/chemical structures (because all are relevant, for instance, in NMR spectrosopy) you have (and want) 10 database entries, each with a single (tautomer-sensitive) InChI. Two definitions of unique.
So my sentence still stands: a chemical structure must calculate a unique InChI, but a InChI might cover more then one chemical structure. On Thu, Feb 19, 2015 at 3:37 PM, Dimitri Maziuk <dmaz...@bmrb.wisc.edu> wrote: > On 2015-02-19 07:27, Markus Sitzmann wrote: >> >> No, a chemical structure must calculate a unique InChI, but a InChI >> might cover more then one chemical structure > > > Heh. I could swear last time I read the description it specifically > mentioned databases. In the database context 'unique' has a specific > well-defined meaning and that is *not* 'more than one'. Now I don't see it > in the official blurbs, only pikiwedia mentions databases. > >> ... there is no precise, universally valid >> definition for "unique molecule". > > > "On two occasions I have been asked, 'Pray, Mr. Babbage, if you put into the > machine wrong figures, will the right answers come out?' I am not able > rightly to apprehend the kind of confusion of ideas that could provoke such > a question." > > Works for 'undefined figures', too. > > Dimitri > > ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk _______________________________________________ Rdkit-discuss mailing list Rdkit-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rdkit-discuss
