Theoretical study of CH3Cl-N2 line shapes in the ν1 band. Line mixing effects in QR doublets and QQk sub-branches

Line coupling and line mixing effects of CH3Cl lines in the ν1 band perturbed by N2 have been investigated. We taken into account non-diagonality exp(−S2) operator within specified spaces as well k-degeneracy transitions (due to double degeneracy j,k levels with k ≠ 0). These should be considered doublets coupled process. A new problem appears calculation when atom-atom potential model is introduced. In order overcome this difficulty, a pragmatic approach proposed. Comparisons theoretically calculated matrix elements W measurements QR(j,k) some QQk sub-branches, which are strongly affected mixing, made. The results show that formalism improved way leads rather accurate predictions.