The ν3 band of 14N18O2: line positions and intensities

The Fourier transform spectrum of a sample prepared by mixing two gaseous species ¹⁸O₂/¹⁴N¹⁶O (1:2) have been recorded in the region of the ν₃ band of nitrogen dioxide. The spectrum contains the lines corresponding to the ν₃ band of the ¹⁴N¹⁸O₂ isotopologue within the 1536-1618 cm⁻¹ spectral range. In total 738 lines of the ν₃ band of this isotopologue were assigned with the rotational quantum numbers N and K_a up to 54 and 10, respectively, corresponding to 948 electron spin-rotation-vibration transitions. The overall measured set of the line positions was used to fit the effective Hamiltonian parameters. The fitted set of the parameters reproduces the observed line positions with an rms of 2.3×10⁻³ cm⁻¹. A selected set of the measured line intensities was used to determine the effective dipole moment parameter describing the line intensities of the ν₃ band. The rms deviation of the fit is 5.8%. Using the fitted set of the effective Hamiltonian parameters and the fitted effective dipole moment parameter (dipole moment derivative $\frac{\partial {\mu }_z}{\partial q_3}$) the list of the calculated line parameters for the ν₃ band of ¹⁴N¹⁸O₂ was generated.