New spectroscopic data on even-parity autoionization states for two-color two-step photoionization of nickel atom

In this study, we selected 5 first excited states of nickel as intermediate energy levels, with a scanning wavelength range of 300-325 nm, to obtain data on 51 even parity autoionization state energy levels and corresponding 141 transitions in the range of 64000-66800 cm-1.

In the dataset, we provide transition wavelengths obtained from scanning 5 first excited states, corresponding energy level positions, energy level widths obtained through Fano fitting, normalized signal intensity, and finally provide the positions, widths, and angular momenta of 51 energy levels by comparing the scanning results of 5 excited state energy levels.