Fig. 2. Experimental and theoretical values for the intrashell transitions.

a–c, Absolute energy of the He-like uranium transition (a), transition energy differences between He-like and Li-like (b) and Be-like and Li-like uranium ions (c). Also shown are past experiments^30,36 and several theoretical predictions (refs. ^{12,30,40–45}). The value for ref. ⁴⁵ in b is obtained from the value differences in refs. ^43,45. Error bars denote ±1 standard deviation. The uncertainties of the measured values are also shown as grey bands.