Search

Currently the following search parameters are supported by the COD search endpoint in http://www.crystallography.net/cod/result:

  • id – a string containing one or more COD IDs separated by a comma (",") or a new line ("\n") symbol. The percent ("%") wild card symbol can be used to specify a range of IDs.;
  • smarts – a substructure query in SMILES arbitrary target specification;
  • text – a keyword that must be contained in the metadata of the entry. The metadata search covers data such as the bibliographic information of the associated publication, common and systematic name of the sample compound and the name of the sample mineral;
  • format – the format in which the results will be returned. Supported formats:
    • html – a html web page displaying the list of COD entries;
    • csv – a csv file containing information about the COD entries. The provided information matches the one provided by the COD MySQL database;
    • json – a json file containing information about the COD entries. The provided information matches the one provided by the COD MySQL database;
    • lst – a txt file containing a list of COD IDs;
    • urls – a txt file containing a list of URLs pointing to the COD CIF files;
    • zip – a zip archive containing CIF files. Please note that there is a limit of how many entries can be returned using this format; in case this limit is reached, a html page with an error message is returned instead;
    • count – the number of COD entries that match the search criteria.
  • formula – the empirical chemical formula of the crystal. Chemical element symbols in the formula must be ordered according to the Hill notation and separated by a space symbol, i.e. "C8 H10 N4 O2";
  • el1, el2, ..., el8 – chemical element symbols that must appear in the chemical formula;
  • nel1, nel2, ..., nel4 – chemical element symbols that must not appear in the chemical formula;
  • strictmin, strictmax – the minimum/maximum number of distinct chemical elements that must appear in the chemical formula;
  • amin, amax – the minimum/maximum value of the lattice parameter a;
  • bmin, bmax – the minimum/maximum value of the lattice parameter b;
  • cmin, cmax – the minimum/maximum value of the lattice parameter c;
  • alpmin, alpmax – the minimum/maximum value of the lattice parameter alpha;
  • betmin, betmax – the minimum/maximum value of the lattice parameter beta;
  • gamin, gamax – the minimum/maximum value of the lattice parameter gamma;
  • vmin, vmax – the minimum/maximum volume of the lattice;
  • minZ, maxZ – the minimum/maximum Z value of the lattice;
  • minZprime, maxZprime – the minimum/maximum Z' value of the lattice;
  • journal – the name of the journal in which the scientific paper describing the crystal structure was published;
  • year – the year of publication of the crystal structure;
  • volume – the volume of the journal where the scientific paper describing the crystal structure was published;
  • issue – the issue of the journal where the scientific paper describing the crystal structure was published;
  • doi – the DOI that links to the online paper in which the crystal structure was published;
  • has_fobs – flag value denoting that entries must have an associated X-ray reflection files (Fobs or Iobs data) in the COD which contain the original reflection intensities used to determine the structures;
  • include_duplicates – flag value denoting that entries that are marked as duplicates of other entries in the COD should not be excluded;
  • include_errors – flag value denoting that entries that are marked as having errors should not be excluded;
  • include_theoretical – flag value denoting that entries that are marked as theoretical should not be excluded.

Entry access

Each database entry can be accessed by appending its ID to http://www.crystallography.net/cod/ and postfixing it by the format, for example, request http://www.crystallography.net/cod/1000000.cif results in retrieval of CIF contents of COD entry 1000000.

Supported formats:

  • cif;
  • hkl – diffraction data (if an entry has associated diffraction data);
  • html – HTML information table for the entry;
  • rdf – entry data in Resource Description Framework format.

Entry access will always return the newest version of the data. Specific revisions could be accessed for CIF and HKL formats by appending revision number preceded by "@", for example, request http://www.crystallography.net/cod/1000000.cif@1 results in retrieval of CIF contents of COD entry 1000000 as of revision 1.