The line strength ratios of lines having a common upper rovibronic level but belonging to different P, Q, and R branches (rotational branching ratios) are, for the first time, measured for the diagonal (v′ = v″ = 0-3) bands of the I1Πg- , J1Δg- → C1Πu± electronic transitions of the D2 molecule. Within the framework of the nonadiabatic model, the ratio of the dipole moments of the 3d1Δg → 2p1Πuand 3d1Πg → 2p1Πu electronic transitions. M2pπ3dΔ/M2pπ3dπ, was obtained from the previously calculated expansion coefficients in the Born- Oppenheimer basis set of perturbed wave functions of the I1Πg- and J1Δg- states of the D2 molecule and experimental values of rotational branching ratios. It was found that, as in the case of H2, there is a significant discrepancy between the values of M2pπ3dΔ/M2pπ3dπ derived from the analysis of experimental data on different electronic transitions: I1Πg- → C1Πu± and J1Δg- → C1Πu±. The reasons for this discrepancy are discussed. At the same time, when the data on both molecules are considered on an equal footing, the effective value of M2pπ3dΔ/M2pπ3dπ = -1.42 ± 0.01, which agrees well with the value of -1.35 ± 0.05 that we obtained earlier for transitions between similar triplet states of H2 and D2 and is close to the estimate of - √2 in the pure precession approximation, corresponds to the whole body of the measured rotational branching ratios of the molecules H2 and D2.
|Number of pages||6|
|Journal||Optics and Spectroscopy (English translation of Optika i Spektroskopiya)|
|State||Published - 1 Dec 1996|
Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics