Reduced effective Hamiltonian for global fitting of C 2 H 2 ro-vibrational lines

Abstract

An effective Hamiltonian describing globally all vibrational-rotational energy levels of C2H2 molecule in the ground electronic state has been written up to fourth order in Amat-Nielsen ordering scheme using symmetry arguments. This Hamiltonian contains all resonance interaction terms within polyad scheme discussed by M.E.Kellman (J. Chem.Phys. 95. 8671 (1991)). D.M.Jonas et al (J.Chem.Phys. 99, 7350 (1993)). M.Abbouti Temsamani and M.Herman (J.Chem.Phys. 103. 593 1 (1995)). The reduction of this effective Hamiltonian by means of unitary transformations has been performed.

Acetylene, 12C2H2: new CRDS data and global vibration-rotation analysis up to 8600 cm-1

“…The global model is presented in Section 5. The results, also updating a previously published global analysis by Perevalov et al [11], are detailed in Section 6 and discussed in Section 7, before concluding in Section 8.…”

“…[40,[49][50][51][52][53]). Inclusion of rotation in the global picture has been already achieved for 12 C 2 H 2 by Perevalov and coworkers [11,54,55], simultaneously considering 7290 lines involving states up to 9700 cm À1 . No detailed related discussion was, however, ever published to complement the limited information provided in a symposium proceedings [54].…”

Vibration-rotation pattern in acetylene. II. Introduction of Coriolis coupling in the global model and analysis of emission spectra of hot acetylene around 3 μm

“…As demonstrated in literature, 10,[13][14][15]21 a global model can be applied to deal with the acetylene vibration-rotation levels up to high vibrational excitation energy. It takes advantage on the well-defined polyad structure of the vibrational levels in the molecule, characterized using the pseudo quantum numbers N r =5v 1 +3v 2 +5v 3 + v 4 + v 5 and 11,22,23 In the global model, diagonal elements represent conventional zero order vibration-rotation energies and off-diagonal elements account for a well-defined set of vibrational anharmonic resonances and for conventional vibrational and rotational l-type resonance terms.…”

Effective dipole moment parameters of 12C2H2 for the 100, 7.7, 1.4, 1.3, 1.2 and 1.0 μm regions

“…Within the framework of the effective operators method, the vibrational-rotational transition moment squared is calculated using the eigenfunctions of the effective Hamiltonian [10]. Parameters of the effective Hamiltonian were fit to the measured line positions between 60 and 10 000 cm À1 .…”

“…This paper continues the series of our studies dealing with the theoretical modeling of the acetylene line intensities within the framework of the effective operator approach [2][3][4][5][6][7][8][9]. This approach is based on the effective Hamiltonian [10] that globally describes the line positions of all of the vibrational-rotational transitions of the C 2 H 2 molecule in its ground electronic state. This effective Hamiltonian considers all of the resonance interactions between vibrational-rotational states up to the sixth order of perturbation theory.…”