UDfA, the UMIST Database for Astrochemistry, launched in 1991, was the world’s first public chemical kinetic database for Astrochemistry. The current implementation of the database, Rate12, contains over 6100 gas-phase, binary reactions among 467 species – 171 neutrals, 268 cations and 28 anions – involving 13 elements to describe chemistry in interstellar and circumstellar clouds. In addition to the parameterised rate coefficients, information is given on the applicable temperature range, accuracy and, where available, links to the original articles from which the data was gathered.

In addition to rate coefficients, the web site at http://www.udfa.net also contains information on deuterium-exchange reactions, state-to-state chemistry involving hydrogen and deuterium, kinetic data on some three-body reactions, binding energies of common neutral species on water ice, and chemical kinetic codes, including plotting routines, and associated tutorial documentation for applications to dark interstellar clouds and circumstellar envelopes.