# Spectroscopic line parameters of NO, NO$_2$, and N$_{2}$O for the HITEMP database

## TL;DR

This paper updates the HITEMP database with new spectroscopic line parameters for NO, NO$_2$, and N$_{2}$O, validated against observations for high-temperature applications.

## Contribution

It introduces updated line lists for NO, NO$_2$, and N$_{2}$O into the HITEMP database, expanding its molecular coverage and validation against observational data.

## Key findings

- Expanded HITEMP database to seven molecules.
- Validated line lists against observational data.
- Prepared data for high-temperature applications.

## Abstract

This work describes the update of NO along with the incorporation of NO$_{2}$ and N$_{2}$O to the HITEMP database. Where appropriate, the HITRAN line lists for the same molecules have also been updated. This work brings the current number of molecules provided by HITEMP to seven. The initial line lists originating from \textit{ab initio} and semi-empirical methods for each molecule have been carefully validated against available observations and, where necessary, adjustments have been made to match observations. We anticipate this work will be applied to a variety of high-temperature environments including astronomical applications, combustion monitoring, and non-local thermodynamic equilibrium conditions.