Torsional Splitting in the Degenerate Vibrational States of 70Ge2H6: Rotation–Torsion Analysis of the ν7 and ν9 Fundamentals

Torsional Line Splittings in the (ν4+ν8)−ν4 Hot Transitions of C2H6 between 1400 and 1510 cm−1

“…For values of ζ smaller than 1 a decrease of the torsional splittings, and even the inversion of the splitting pattern, should be expected. These predictions are clearly supported by observations in the spectra of C 2 D 6 (8) and 70 Ge 2 H 6 (9,10). Thus the torsional splitting in the v 8 = 1 degenerate vibrational state, with ζ 8 = −0.32 according to Ref.…”

“…We found Q and P transitions for K K < 0 and Q and R transitions for K K > 0. The assignments could thus be checked by the method of lower state combination differences, making use of values of B, D J , and D J K of the v 4 = 1 state determined previously (10). R Q 0 transitions and a few R R 0 and R P 0 transitions were assigned for both torsional components.…”

Torsional Splittings in Small-Amplitude Vibrational Fundamental States of Methanol-Type Molecules

“…Although numerical eigenvectors will not be quantitatively examined in this work, it would clearly be instructive to compare, based on transformations such as Eqs. [15] and [16] of Ref. (6), eigenvectors described from the point of view of this paper, where torsional A-E mixing is allowed, with their counterparts belonging to the same eigenvalue but described from the usual point of view, where all degenerate vibrational coordinates have been converted to nondegenerate coordinates and where torsional A-E mixing is forbidden.…”

“…[16], or by setting k 2 = k 4 = 0, and thus considering only vibration-torsion interaction terms involving e ±iγ . These seven fitting parameters can be related to the three parameters ω, λ, and µ of Wang and Perry (4).…”

“…(A notable exception, however, is the extensive work on ethane-like molecules (7)(8)(9)(10)(11)(12)(13)(14)(15)(16). In particular, see the discussion of Ref.…”