Analysis of the submillimetre Ar:HI Σ bending transition as a test of a morphed potential

Abstract

Σ bending transitions in the argon:hydrogen–iodide dimer have been analyzed following observation using a frequency and phase stabilized co-axially configured submillimetre supersonic jet spectrometer. This transition is from the ground state Ar–IH isomer to the excited state Ar–HI isomer. Molecular constants with one standard deviation to the fit are determined to be for the ground state: B_J = 1034.08372 (25) MHz, D_J = 10.5962 (77) kHz, H_J = −1.678 (69) Hz, χ_aa = −1114.4014 (12) MHz, D_χaa = 82.3 (12) kHz. The corresponding constants for the newly determined upper state are: ν₀ = 263128.0649 (14) MHz, B_J = 876.47909 (21) MHz, D_J = 5.3692 (52) kHz, H_J = 1.669 (38) Hz, χ_aa = −535.421 (10) MHz, D_χaa = −106.2 (11) kHz. This data is used to test the accuracy of currently available ab initio and morphed potentials for the complex and to propose refinement of the latter potential.