Pressure broadening calculations for OH in collisions with argon: Rotational, vibrational, and electronic transitions

Abstract

Collisional parameters describing both the pressure-induced broadening and shifting of isolated lines in the spectrum of the hydroxyl radical in collisions with argon have been determined through quantum scattering calculations using accurate potential energy surfaces describing the OH(X 2 Π,A 2 Σ + )-Ar interactions. These calculations have been carried for pure rotational, vibrational, and electronic transitions. The calculated pressure broadening coefficients are in good agreement with the available measurements in the microwave, infrared, and ultraviolet spectral regions. Computed pressure broadening coefficients as a function of temperature are reported for these three types of transitions.

Recent advances in collisional effects on spectra of molecular gases and their practical consequences

“…For instance, these advanced computational capabilities have enabled, for H 2 -He, consideration of the effects of the centrifugal distortion of the PES or of rovibrational potential coupling terms [156,200]. PESs for the active molecule in the ground state or in an excited electronic state also have enabled calculations of pressure-broadening and -shifting coefficients for rotational, rovibrational and rovibronic lines [201,202]. Furthermore, CC predictions for asymmetric-top molecules in a bath of diatomics are nowadays feasible.…”