“…There has been extensive laboratory work on Ni XVI and other lines of the Al-like isoelectronic sequence from laser-produced plasma experiments (see, for example, Churilov and Levashov [15], Redfors and Litzén [16]), beam-foil spectroscopy (see, for example, Träbert et al [17], Buchet-Poulizac and Buchet [20], Pinnington et al [21]), spark spectra (Jupén and Curtis [22]), and tokamak spectra (Jupén and Curtis [22], Hinnov et al [19]). Specifically, in Table I the experimental energies were obtained as follows: level 2, from Hinnov et al [19]; levels 7-12, from Shirai et al [14]; levels 4 -6, 13-15, 21-24, and 26 -40, from Churilov and Levashov [15]; level 3, from Redfors and Litzén [16]; levels 16 -18, from Träbert et al [17]; and level 19, from Levashov et al [18].…”