title: Improved collisional excitation rates for interstellar water.
abstract: Theoretical rate constants among the lowest 45 para and 45 ortho rotational levels of water in collisions with He atoms have been calculated for temperatures between 20 and 2000 K using a recently improved theoretical interaction potential.  These values are about 30%-40% larger than those reported previously (Palma et al. 1988b) but relative sizes of different state-to-state rates have not changed significantly.  Successive improvements to the theoretical description of this system now appear to have converged.
authors.affiliation: NASA Goddard Space Flight Center, Institute for Space Studies, New York 10025.
authors.forename: S
authors.initials: S
authors.lastname: Green
authors.forename: S
authors.initials: S
authors.lastname: Maluendes
authors.forename: A D
authors.initials: AD
authors.lastname: McLean
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D055598:Chemical Phenomena; D015392:Chemistry, Inorganic; D005118:Extraterrestrial Environment; D006371:Helium; D008872:Microwaves; D008956:Models, Chemical; D008958:Models, Molecular; D016082:Solar System; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D006371:Helium