Rotational analysis of hydroxyl vibration–rotation emission bands: Molecular constants for OH <i>X</i>²Π, 6 ≤ ν ≤ 10

Abstract

Seven vibration–rotation emission bands of the hydroxyl radical with 6 ≤ ν′ ≤10 have been recorded photoelectrically in the range λ6250–8500 Å. The first reliable constants for levels 6 ≤ ν ≤10 of OH X 2 Π are obtained by direct least-squares fitting of the measured line frequencies. The vibrational dependences of the Λ-doubling parameters (p and q) and the spin–orbit coupling constant (A) are well defined. A minimum value of A ν is found at ν = 7.