Steric proficiency of polar 2Σ molecules in congruent electric and magnetic fields

Abstract

We examine the eigenenergies, spatial orientation, and alignment of polar ²Σ molecules subject to congruent static electric and magnetic fields. In the presence of a magnetic field only, certain pairs of Zeeman states with opposite parity intersect. Introducing a congruent electric field connects such states, thereby creating avoided crossings and a first-order Stark effect which can strongly orient the states. Since this effect, termed ‘‘steric proficiency, ’’ operates over a narrow range of magnetic field strength, with amplitude determined by the electric dipole interaction, it should find use both for state selection and as a diagnostic tool for assigning spectral transitions. Other aspects are illustrated by strategies suggested for some prospective applications. These include a way to test whether formation of the A ²Σ⁺ excited electronic state of NaO in the Na+O₃ reaction results from the orientation dependence of electron transfer, and techniques to enable the ground ²Σ⁺ states of RbO and CsO, produced by reacting NO₂ with alkali atoms, to be loaded into a magnetic trap.