Infrared spectrum of ozone in the 4600 and 5300 cm(-1) regions: High order accidental resonances through the analysis of nu(1)+2 nu(2)+3 nu(3)-nu(2), nu(1)+2 nu(2)+3 nu(3), and 4 nu(1)+nu(3) bands

The very weak bands nu(1) + 2 nu(2) + 3 nu(3) and 4 nu(1) + nu(3) of O-16(3) have been observed for the first time, using the Fourier transform spectrometer (FTS) of Reims and the usual experimental setup providing a large product p X l of approximately 38 Torr x 36 m. The upper levels of these A-type bands which are rather close in energy (they appear respectively at 5291.722 and 5307.790 cm(-1)) belong to two different sets of interacting polyads. To correctly reproduce the rotation-vibration energy levels and account for the observed perturbations, both bands are treated in a dyad approximation: the (123) state in the Coriolis resonance with the (330) state, and the (401) state in the Coriolis resonance with the (024) state. The assignments of the rotation-vibration levels of the (123) state are confirmed by measurements of line positions of the hot band nu(1) + 2 nu(2) + 3 nu(3) - nu(2) which has also been observed for the first time. The fits are very satisfactory: the r.m.s. deviation for 249 energy levels of the (123) state is 2.4 x 10(-3) cm(-1) and is 2.0 x 10(-3) cm(-1) for 266 levels of the (401) state. These r.m.s. are near experimental accuracy. Transition moments for the three observed bands are determined from measured line intensities. (C) 1997 Academic Press.