  We describe a new atomic and molecular database we developed for use in the
spectral synthesis code Cloudy. The design of Stout is driven by the data needs
of Cloudy, which simulates molecular, atomic, and ionized gas with kinetic
temperatures 2.8 K < T < 1e10 K and densities spanning the low to high-density
limits. The radiation field between photon energies $10^{-8}$ Ry and 100 MeV is
considered, along with all atoms and ions of the lightest 30 elements, and ~100
molecules. For ease of maintenance, the data are stored in a format as close as
possible to the original data sources. Few data sources include the full range
of data we need. We describe how we fill in the gaps in the data or extrapolate
rates beyond their tabulated range. We tabulate data sources both for the
atomic spectroscopic parameters and for collision data for the next release of
Cloudy. This is not intended as a review of the current status of atomic data,
but rather a description of the features of the database which we will build
upon.
