GLOBAL VIBRATION-ROTATION ANALYSIS IN ACETYLENE: $^{12}$CH$^{13}$CH

Author Institution: Service de Chimie quantique et Photophysique, CP160/09, Universite Libre de Bruxelles (U.L.B.), Ave. F.-D. Roosevelt, 50, B-1050, Bruxelles, Belgium; Laboratoire de Spectroscopie Moleculaire, Universite Catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-La-Neuve, Belgium; Dipartimento di Chimica Fisica e Inorganica, Universita di Bologna, Viale Risorgimento, 4, I-40136, Bologna, ItalyAll known vibration-rotation absorption lines of $^{12}$CH$^{13}$CH accessing levels up to 6750 cm$^{-1}$ were gathered from the lite\-rature. They were fitted simultaneously to $J$-dependent Hamiltonian matrices exploiting the well known vibrational polyad or cluster block-diagonalization, in terms of the pseudo quantum numbers $N_{s}$ = $v_{1}$+$v_{2}$+$v_{3}$ and $N_{r}$ = 5$v_{1}$+3$v_{2}$+5$v_{3}$+$v_{4}$+$v_{5}$, and accounting also for $l$-parity and $e$/$f$ symmetry properties. The anharmonic interaction coupling terms known to occur from a pure vibrational fit in this acetylene isotopologue were included in the model. The results will be presented and discussed