Theory of Gas Phase Scattering and Reactivity for Astrochemistry
  Because of the very peculiar conditions of chemistry in many astrophysical
gases (low densities, mostly low temperatures, kinetics-dominated chemical
evolution), great efforts have been devoted to study molecular signatures and
chemical evolution. While experiments are being performed in many laboratories,
it appears that the efforts directed towards theoretical works are not as
strong.
  This report deals with the present status of chemical physics/physical
chemistry theory, for the qualitative and quantitative understanding of
kinetics of molecular scattering, being it reactive or inelastic. By gathering
several types of expertise, from applied mathematics to physical chemistry,
dialog is made possible, as a step towards new and more adapted theoretical
frameworks, capable of meeting the theoretical, methodological and numerical
challenges of kinetics-dominated gas phase chemistry in astrophysical
environments.
  A state of the art panorama is presented, alongside present-day strengths and
shortcomings. However, coverage is not complete, being limited in this report
to actual attendance of the workshop. Some paths towards relevant progress are
proposed.
