High temperature infrared spectrum of sodium iodide (NaI)

•Measurements are reported for the infrared spectrum of NaI vapor from 200 to 275cm−1.•Dunham potential constants are given for the fundamental band of NaI.•The Herman–Wallis effect was used to determine the fundamental band transition moment.•The vibrational dependence of the ν=n+1←n transitions is measured.•The calculated spectrum is shown to agree with the observed spectrum.