This volume provides critically evaluated data on free molecules, obtained from infrared spectroscopy and related experimental and theoretical investigations. It is divided into four subvolumes which look at diatomic molecules, linear triatomic molecules, nonlinear triatomic molecules and polyatomic molecules. The present subvolume deals with the linear triatomic nitrous oxide molecule N2O (NNO). Both the normal isotope species 14N14N6O and eleven of its isotopic varieties have been considered and the tables are preceded by an additional index to help the search for specific information. Systems requirements: Windows 3.X, 95 MAC, UNIX, Ca 4 MB RAM and 8 MB hard disk space needed for the Adobe Acrobat Reader 3.0 with full text search engine.