This is a compilation of approximately 923,000 allowed, intercombination and forbidden atomic transitions with wavelengths in the range from 0.5 Å to 1000 µm. It's primary intention is to allow the identification of observed atomic absorption or emission features. The wavelengths in this list are all calculated from the difference between the energy of the upper and lower level of the transition. No attempt has been made to include observed wavelengths. Most of the atomic energy level data have been taken from the Atomic Spectra Database provided by the National Institute of Standards and Technology (NIST).