ExoMol line lists–LIX. High-temperature line list for N2O

Abstract

ABSTRACT New hot line lists for five isotopologues of N$_2$O called TYM are presented, for the parent $^{14}$N$_2$$^{16}$O and 4 singly substituted species $^{14}$N$_2$$^{17}$O, $^{14}$N$_2$$^{18}$O, $^{14}$N$^{15}$N$^{16}$O and $^{15}$N$^{14}$N$^{16}$O. The line lists have been computed with the variational program TROVE (Theoretical ROVibrational Energies) using a new empirical potential energy surface (PES) and an accurate ab initio dipole moment surface of N$_2$O Ames-1. The PES was obtained by fitting to experimentally derived energies of N$_2$O compiled using the well established measured active rotation vibration energy levels (MARVEL) procedure. Here we also introduce an ‘artificial symmetry group’ $C_{n \text{s}}(\text{AEM})$ for an efficient construction of rotation-vibrational basis set of a linear non-symmetric triatomic molecule of the XYZ type. The line lists cover the rotational excitations up to $J=160$ and the wavenumber range up to 20000 cm$^{-1}$. MARVEL energies are also used to improve predicted line positions resulting in excellent agreement with the available experimental spectra, as demonstrated. An extensive comparison with existing line lists for N$_2$O HITRAN, HITEMP, NOSL-296, NOSD-1000, and Ames-296K is provided. The TYM line lists are freely accessible from www.exomol.com.

Topics & Concepts