The UMIST Database for Astrochemistry 2012

We present the fifth release of the UMIST Database for Astrochemistry (UDfA). The new reaction network contains 6173 gas-phase<br/>reactions, involving 467 species, 47 of which are new to this release. We have updated rate coefficients across all reaction types.<br/>We have included 1171 new anion reactions and updated and reviewed all photorates. In addition to the usual reaction network, we<br/>also now include, for download, state-specific deuterated rate coefficients, deuterium exchange reactions and a list of surface binding<br/>energies for many neutral species. Where possible, we have referenced the original source of all new and existing data. We have tested<br/>the main reaction network using a dark cloud model and a carbon-rich circumstellar envelope model. We present and briefly discuss<br/>the results of these models.