High-Temperature Line List of NO ₂ ⁺ for Generating Molecular Spectra and Absorption/Emission Cross Sections

The molecular line list of NO₂⁺ is of great atmospheric significance, especially for related spectral characterization and radiative transfer calculation. Using robust first-principles methods, we presented the first comprehensive line list of ground-state NO₂⁺. Analytical potential energy surface and dipole moment surface were constructed based on 8991 <i>ab initio</i> points from coupled-cluster calculations, in which the core-valence electron correlation and scalar relativistic effects were considered in the calculations of potential energy. The variational nuclear motion program TROVE was used to obtain the ro-vibrational energy levels, wave function, and Einstein <i>A</i> coefficients. The line list contains almost 25.1 million transitions between 736 thousand energy levels with rotational excitation up to 200, which covers the wavenumber range of 0-9000 cm^-1 and is suitable for temperatures up to 3000 K.