Sharp and window resonances in the 4d photoabsorption spectrum of Eu+ ions -: art. no. 032716

We have studied the 4d photoabsorption process of Eu+ ions by the linear-density-response theory with the density-functional theory and an optimized effective potential and self-interaction correction. Different from the recent experimental observation, which found that the 4d photoabsorption spectrum of Eu+ ions is almost the same as that of neutral Eu atoms, our calculated 4d photoabsorption spectrum of Eu+ ions shows many sharp and window resonances, which do not appear in case of neutral Eu atoms. The discrepancies between the experimental observation and our calculation are due to the experimental energy resolution. The convoluted spectrum with the experimental energy resolution is in good agreement with the experimental observation. Moreover, we predict the 4d photoabsorption spectra with several given energy resolutions, which call for a further higher-resolution experiment.