High precision spectrum of N2O at 4.5 μm and determination of molecular constants for the ν3 and the (ν2 + ν3 − ν2) bands

A high precision wavenumber calibration has been achieved for the spectrum of N₂O at 4.5 μm. The values of the wavenumbers are reported for the (00°1-00°0) and for the (01¹1-01¹0) transitions. A new set of molecular constants is given for the upper and lower levels of these two transitions. In particular, the value of the H constant for the ground state (?2.02 ± 0.4) × 10^?13 cm^?1 determined in this work is significantly different from previous results.