This project focuses the ubiquitous ion atmosphere, which profoundly influences the overall folding of all complex RNAs. We have chosen to work with simple, structurally well-defined constructs to isolate electrostatic interactions involving the ion atmosphere to their basic core elements. This basic, comprehensive, and rich data is used to rigorously develop and test state-of-the-art electrostatic models and theories that can be applied for prediction and used as tools for design in more complicated RNA systems.