Infrared study of the X²Π ν = 0, 1, 2 levels of ¹⁴N¹⁶O. Preliminary results on the ν = 0, 1 levels of ¹⁴N¹⁷O, ¹⁴N¹⁸O, and ¹⁵N¹⁶O

The analysis of high resolution Fourier spectra (2.5 × 10 −3 cm −1 ) led to accurate molecular constants for the vibrational levels ν = 0, 1, 2 of the X 2 Π state of 14 N 16 O and of the levels ν = 0, 1 of the X 2 Π state of 14 N 17 O, 14 N 18 O, and 15 N 16 O. A computer program has been written to directly reduce the data. It is shown that the expected variations for the different parameters with isotope substitution are well verified. Values of A J (e) and γ e are determined and discussed.