Discrete Structure in the Spectrum of Sodium Iodide Vapor

Abstract

The fluctuation bands of NaI are shown to be intensity alternations in a resolved band system. The fluctuations, spaced by about 300 cm⁻¹, are associated primarily with the ground‐state vibrational spacing; the band structure spacing of 36 cm⁻¹ is probably to be associated with the vibrational frequency of the excited state. The discrete line spectrum occurs without any break from 2945 to 5400 Å. From the low‐wavelength limit a dissociation energy for the ground state, $D_0\text{\hspace{0.17em}=\hspace{0.17em}(26 343\hspace{0.17em}±\hspace{0.17em}232)}{\mathrm{cm}}^{\text{−1}}$ , is derived.