Resonance functions in the theory of collisional broadening of molecule spectral lines at low temperatures

Eleven resonance functions are calculated in the exact trajectory model, which can be used for calculation of broadening coefficients γ of molecular lines during interactions with atoms of inert gases at very low temperatures. These functions correspond to the atom-atom potential and the potential V(R, θ) written in terms of Legendre polynomials. The functions are represented in analytical form. The broadening coefficients γ are calculated for absorption lines of CO perturbed by He and Ar at temperatures T from 300 to 2 K using the potential V(R, θ). It is shown that the dependence γ(T) for low temperatures T is determined by the potential well depth. For the CO–He system, a comparison with the experimental data is performed.