Spectroscopy and radiative transfer are rapidly growing fields within atmospheric and planetary science with implications for weather, climate, biogeochemical cycles, air quality on Earth, as well as the physics and evolution of planetary atmospheres in our solar system and beyond. Remote sensing and modeling atmospheric composition of the Earth, of other planets in our solar system, or of planets orbiting other stars require detailed knowledge of how radiation and matter interact in planetary atmospheres. This includes knowledge of how stellar or thermal radiation propagates through...