Speed-dependent broadening and line mixing in CH4 perturbed by Ar and N2 from multispectrum fits

摘要: Abstract Speed-dependent broadenings and shifts have been determined for the P R branches of ν 3 band CH 4 perturbed by Ar N 2 using a multispectrum fitting analysis high-resolution tunable difference-frequency laser spectra recorded at pressures ≤67 kPa. For J ≥3, tetrahedral fine structure components in each manifold are collisionally coupled exhibit significant interference. The lines treated speed-dependent first-order line-mixing profile compared to speed-independent full relaxation matrix inversion procedure with off-diagonal coupling elements calculated from an atom–atom Lennard–Jones potential model.