Comprehensive study of the pentad bending triad region of germane: Positions, strengths, widths and shifts of lines in the 2ν2, ν2+ν4 and 2ν4 bands of 70GeH4, 72GeH4, 73GeH4, 74GeH4, 76GeH4. (March 2021) - Ulenikov, O.N.
Highlights: Positions, strengths, widths and shifts of lines are recorded for the pentad bending triad of M GeH 4 ( M = 70, 72, 73, 74, 76 ) . Effective dipole moment parameters of the pentad bending triad of MGeH4 are determined. List of 164220transitions is presented. Abstract: The high resolution infrared spectra of GeH 4 in its natural abundance were recorded with a Bruker IFS125 HR Fourier transform infrared spectrometer at an optical resolution of 0.003 cm − 1 and analyzed in the region of 1400–2000 cm − 1 where the first bending overtone 2 ν 2, 2 ν 4 and combinational ν 2 + ν 4 bands are located. Ro–vibrational line positions and energies of the 70 GeH 4 species were analysed for the first time and line positions and energies of the 72 GeH 4 and 74 GeH 4 species were improved considerably in comparison with the preceding studies. The numbers of 2316/2406/873/3007/2257 transitions with J max = 21/23/18/22/19 of the 2 ν 2 ( A 1 − and E − type sub–bands), 2 ν 4 ( A 1 −, E − and F 2 − type sub–bands) and ν 2 + ν 4 ( F 1 − and F 2 − type sub–bands) bands of the 70 GeH 4, 72 GeH 4, 73 GeH 4, 74 GeH 4, and 76 GeH 4 molecules were used in the joint weighted fit of experimentally assigned transitions with the Hamiltonian model which takes the resonance interactions between the seven, ( 0200, A 1 ), ( 0200, E ), ( 0101, F 1 ), ( 0101, F 2 ), ( 0002, A 1 ), ( 0002, E ) and ( 0002, F 2 ), vibrational states into account. From our preceding studies 5563 hot band transitions were also taken into account. As the result of a joint fit, a set of 129 fitted parameters was obtained which reproduce the initial 16422 experimental (including "hot") transitions of five isotopologues with the d rms = 3.26 × 10 − 4 cm − 1 . A line strength analysis of the 1697 experimentally recorded transitions of all species was made by the fit of their line shapes with the Hartmann-Tran profile and 13 effective dipole moment parameters were obtained from the weighted fit which reproduce the initial experimental line strengths with the d rms = 3.4 % . Self–broadening coefficients of 993 lines and self–shift coefficients of 674 lines were determined from the multi–spectrum analysis of these lines.