Partition functions and dissociation equilibrium constants are presented for
291 diatomic molecules for temperatures in the range from near absolute zero to
10000 K, thus providing data for many diatomic molecules of astrophysical
interest at low temperature. The calculations are based on molecular
spectroscopic data from the book of Huber and Herzberg with significant
improvements from the literature, especially updated data for ground states of
many of the most important molecules by Irikura. Dissociation energies are
collated from compilations of experimental and theoretical values. Partition
functions for 284 species of atoms for all elements from H to U are also
presented based on data collected at NIST. The calculated data are expected to
be useful for modelling a range of low density astrophysical environments,
especially star-forming regions, protoplanetary disks, the interstellar medium,
and planetary and cool stellar atmospheres. The input data, which will be made
available electronically, also provides a possible foundation for future
improvement by the community.Comment: 13 pages, 8 figures, 8 tables. Full tables 1, 2, 4, 5, 6, 7 and 8 to
be made available in electronic form at the CDS via anonymous ftp to
cdsarc.u-strasbg.fr (130.79.128.5) or via
http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A
