Term energy analysis of iron monohydride (FeH)

MARVEL software was used to perform a global fit on all FeH transitions available in the literature to create an optimized and comprehensive term energy list. The diverse types of data, data sources, and electronic transitions that were used for this fit are organized and tabulated. To improve the fit, inconsistencies in the F 4 Δ -X 4 Δ analysis published in 1987 were fixed using modern computation and visualization techniques. F 4 Δ -A 4 Π transitions were identified in spectra published in the Kitt Peak archive and added to the fit. Also, several laser excitation and Fourier transform spectrometer measurements taken in our lab were added, including those from the newly discovered I 4 Φ electronic state. The final term energy list and transition list are given in the supplementary material. • Iron monohydride transitions were analysed from 16 sources plus those we measured. • 5190 transitions were inputted into MARVEL to generate 1648 energy levels. • Transition assignments from previous literature were updated when necessary. • Updated term energies are significantly more consistent with all the transitions.