TY - JOUR

T1 - The radiative characteristics of the rovibronic states of the hydrogen molecule

T2 - IV. Relative probabilities of the r3II- g, s3 Δ -g → c 3II±u spontaneous transitions of the H2 molecule

AU - Astashkevich, S. A.

AU - Lavrov, B. P.

AU - Modin, A. V.

AU - Umrikhin, I. S.

PY - 2008/1/1

Y1 - 2008/1/1

N2 - A statistical analysis of the available literature data and data obtained in this work on the wave numbers of the lines that appear in triplet-triplet rovibronic transitions of the H2 molecule was performed. This allowed us to verify and refine the controversial identification of spectral lines and find the optimum rovibronic level energy values for the c3II± u, and s3 Δ -g states. The ratios between the line strengths of the P, Q, and R branches of the (4dπ) r s3 Δ -g, s3 Δ -g → (4d?) s(2pδ) c band systems of the H 2 molecule were measured systematically. The calculation results obtained in the Frank-Condon approximation differed substantially (by up to two orders of magnitude) from the experimental data. The dependences of the ratios between rovibronic line strengths of the r c and s c transitions on the rotational quantum number N' of the upper level were found to correlate with each other. The deviations of adiabatic theory increase as N' grows, which is evidence of an important role played by electronic-rotational interactions in the perturbation of transition probabilities. The experimental ratios between the probabilities of rovibronic transitions satisfactorily agree with the results of calculations within the framework of the simple nonadiabatic model taking into account electronic-rotational interaction of radiating adiabatic states in the approximation of pure precession. The dependences of transition probabilities on N' were obtained for the first time for the first four diagonal bands of the r3 II -g s3 Δ -g → →, c3II±u transitions.

AB - A statistical analysis of the available literature data and data obtained in this work on the wave numbers of the lines that appear in triplet-triplet rovibronic transitions of the H2 molecule was performed. This allowed us to verify and refine the controversial identification of spectral lines and find the optimum rovibronic level energy values for the c3II± u, and s3 Δ -g states. The ratios between the line strengths of the P, Q, and R branches of the (4dπ) r s3 Δ -g, s3 Δ -g → (4d?) s(2pδ) c band systems of the H 2 molecule were measured systematically. The calculation results obtained in the Frank-Condon approximation differed substantially (by up to two orders of magnitude) from the experimental data. The dependences of the ratios between rovibronic line strengths of the r c and s c transitions on the rotational quantum number N' of the upper level were found to correlate with each other. The deviations of adiabatic theory increase as N' grows, which is evidence of an important role played by electronic-rotational interactions in the perturbation of transition probabilities. The experimental ratios between the probabilities of rovibronic transitions satisfactorily agree with the results of calculations within the framework of the simple nonadiabatic model taking into account electronic-rotational interaction of radiating adiabatic states in the approximation of pure precession. The dependences of transition probabilities on N' were obtained for the first time for the first four diagonal bands of the r3 II -g s3 Δ -g → →, c3II±u transitions.

UR - http://www.scopus.com/inward/record.url?scp=84869189856&partnerID=8YFLogxK

U2 - 10.1134/S1990793108010041

DO - 10.1134/S1990793108010041

M3 - Article

AN - SCOPUS:84869189856

VL - 2

SP - 16

EP - 31

JO - Russian Journal of Physical Chemistry B

JF - Russian Journal of Physical Chemistry B

SN - 1990-7931

IS - 1

ER -