This portal provides energies, transition matrix elements, transition rates, radiative lifetimes, branching ratios, polarizabilities, and hyperfine constants for atoms and ions. The data are calculated using a high-precision state-of-the-art linearized coupled-cluster method. All values include estimated uncertainties. Data for more systems will be added in the future. Experimental values are included with references where high-precision data are available. Future updates will also include releases of user-friendly atomic codes. We seek community input to improve the portal and guide the next stages of the project. Learn more