High resolution Fourier transform absorption spectra of the 14 N 16 O 2 molecule recorded in the 3000-3400 cm 01 and 1520-1600 cm 01 spectral regions have been analyzed. In this way lines of the 2n 3 , 4n 2 , 2n 2 / n 3 , and 2n 3 0 n 3 bands of 14 N 16 O 2 have been assigned with K a values ranging from 0 to 8 and N values up to 60. The spin-rotation energy levels were very satisfactorily reproduced using a theoretical model which takes explicitly into account both the Coriolis interaction between the spin-rotation levels of the (021) vibrational state and those of (040) and of (002), and the spinrotation resonances within ( ), (040), and (002). As a consequence, precise vibrational band centers and rotational, spin-rotation, and coupling constants were obtained for the triad {( ), ( ), (021)} of interacting states of 14 N 16 O 2 . In addition, using a large set of individual 2n 3 , 4n 2 , and 2n 2 / n 3 experimental line intensities at 3.2 mm, we have determined precisely the 2n 2 / n 3 and 2n 3 transition moment constants of 14 N 16 O 2 . On the other hand, the transition moment constants of the 2n 3 0 n 3 and 2n 2 / n 3 0 2n 2 bands were derived from those of the corresponding n 3 cold band. Finally, a comprehensive list of line positions and intensities of the interacting 4n 2 , 2n 3 , 2n 2 / n 3 , and 2n 3 0 n 3 bands of 14 N 16 O 2 has been generated at 3.2 mm and 6.2 mm, respectively.