The laser magnetic resonance spectrum of the HCO radical at 5.3 μm

The CO stretching fundamental ν₂ of the HCO radical has been studied using CO laser magnetic resonance. The transitions have been assigned largely on the basis of their Zeeman patterns as low N and K_a members of P, Q, and R branches of the a-component (ΔK_a = 0) of the hybrid band. No b-type transitions have been detected. Measurements of the resonances have been used to determine the vibrational interval (1868.1714(5) cm^?1) and the major molecular parameters for HCO in the (0,1,0) level. The changes in values of these parameters from their ground-state values are remarkably small.