Theoretical Study of Collision-Induced Double Transitions in CO(2)-X(2) (X(2) = H(2), N(2), and O(2)) Pairs

The double vibrational collision-induced absorptions CO(2) (nu(3) = 1) + X(2) (nu(1) = 1) <-- CO(2) (nu(3) = 0) + X(2) (nu(1) = 0), for X(2) = H(2), N(2), and O(2) are studied on the basis of quantum lineshapes computed using isotropic potentials and dipole-induced dipole functions. The linestrengths and energies of the vibration-rotation transitions are treated explicitly for X(2) and utilizing the HITRAN database for CO(2). From the frequency-dependent absorption profiles, the integrated absorption intensities are determined to be 7.2 +/- 1.2, 1.2 +/- 0.1, and 1.1 +/- 0.2 (10(-4) cm(-2) amagat(-2)) for the H(2), N(2), and O(2) collision partners, respectively. The integrated intensities for H(2) and N(2) agree well with previously measured and calculated results, while the value for O(2), which represents the first theoretical determination for this absorption, is approximately four times greater than the only experimental measurement (0.29 x 10(-4) cm(-2) amagat(-2)). Copyright 2001 Academic Press.