Amaro, Pedro, Filippo Fratini, Laleh Safari, Jorge Machado, Mauro Guerra, Paul Indelicato, and José Paulo Santos. "{Relativistic evaluation of the two-photon decay of the metastable $1s^2\,2s\,2p\,^3P_0$ state in berylliumlike ions with an effective-potential model}." Physical Review A. 93 (2016): 032502.