The Double Minimum Problem Applied to Potassium Hydrogen Fluoride

Abstract
The doublet character of the infra‐red absorption line at 2.67μ of solid potassium hydrogen fluoride is due to the ``tunnel effect.'' The proton has two potential minima between the fluorine nuclei in the FHF ion. The distance of a minimum to the center of the ion is 0.26A. The height of the potential hill is 33,400 calories.