Knowledge Bank

Quantum assignments and line-intensity measures based on a new simultaneous analysis of the $v2$ and $v4$ bands of $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CH4$ have been carried out using infrared spectra recorded with a resolution of $0.06cm-1$. Line-by-line intensity measurements were compared with the theoretical relative intensities derived from the third-order Hamiltonian model of Pierre at $al,1$ and corrected for the $v2-v4$ coriolis interaction. Total intergrated band strengths were computed for both $v2$ and $v4$. Deviations from the relative intensity distributions were found and their origins discussed.