Laser spectroscopy of the diatomic van der Waals molecule NaNe

Abstract

We present a thorough spectroscopic study of the van der Waals molecule NaNe. Our molecular beam apparatus, laser scanning system, and frequency reference technique are described in detail. Methods of rotational analysis are discussed. Descriptions of the observed vibration–rotation bands in the A ²Π_r–X ²Σ⁺ and B ²Σ⁺–X ²Σ⁺ manifolds are presented. Perturbations in the observed spectra are discussed. Long range analysis techniques are used to determine the vibrational quantum numbering from observed isotopic shifts and to determine excited and ground state potential parameters. We find D_eA=145±⁰₅ cm⁻¹ at R_eA=5.1(1)a₀, D_eX=8.1(9) cm⁻¹ at R_eX=10.0(1)a₀, and D_eB?3.0(5) cm⁻¹ at R_eB?14.4(3)a₀.