Improved Co2 Ir Line List For 1500k - 3000k

Huang, Xinchuan

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https://hdl.handle.net/2142/116734 Copy

Description

Title

Improved Co2 Ir Line List For 1500k - 3000k

Author(s)

Huang, Xinchuan

Contributor(s)

• Lee, Timothy J.
• Freedman, Richard S.
• Schwenke, David

Issue Date

2022-06-21

Keyword(s)

Linelists

Abstract

Previously published high temperature CO$_{2}$ IR line lists either do not cover the region $>$10,000 \wn, or lack convergence due to cutoffs, or have noticeable noises. We report a new CO$_{2}$ IR line list improved for applications in the range from 1500K to 3000K, denoted Ames-3000K.\footnote{Funded by NASA Grants 18-APRA18\_0013 and NASA$/$SETI Co-op Agreements 80NSSC20K1358 \& 80NSSC19K1036.} With at least 7 billion lines of CO$_{2}$ 626, 636, 628 and 627, it covers the whole range from 0 to 20,000 \wn. We estimate it is converged up to 20,000 \wn at 1000K, up to 10,000-15,000 \wn at 2000K, or up to 5000-8000 \wn at 3000K, but needs further PES and DMS improvements for 4000K and above. Compared to our earlier CO$_{2}$ line list work, e.g., Ames-296K/1000K and Ames-4000K, the Ames-3000K combines the advantages of two sets of IR line lists. The 1$^{st}$ set focuses on the low energy region, with intensity computed using the best available Ames-2 PES, and the best available ab initio DMS, Ames-2021. The Ames-2021 DMS based IR intensity represents a major improvement for theoretical CO$_{2}$ intensity calculations. Our predictions for the CO$_{2}$ 2001x and 3001x bands matched high accurate experiments to -0.1$\pm$0.1$\%$ (NIST) or 0.2$\pm$0.4$\%$ (DLR). But the Ames-2021 DMS was fit only up to 30,000 \wn. The 2$^{nd}$ set of line lists provides reliable prediction for IR transitions with E$'$ up to 36,000 \wn. Related calculations were run on a different PES, X01d. To enhance the success rate of Ames vs. CDSD matches in the range of 15,000 - 22,000 \wn, the X01d PES was refined specifically using selected CDSD Effective Hamiltonian model levels up to 24,000 \wn, but at a price of the accuracy reduced for lower energy levels and transitions. The ab initio dipole dataset of Ames-2021 DMS was refitted with 40,000 \wn cutoff to generate an DMS suitable for the intensity calculation at higher energy, denoted Ames-2021-40K. The two sets of line lists are then combined and updated using the CDSD energy levels to get accurate line positions for E$'<$15,000 \wn and J$<$150 transitions. The accuracy, consistency, and issues of the Ames-3000K IR line list will be evaluated by comparing with high temperature experiments and databases.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116734

DOI

https://doi.org/10.15278/isms.2022.TC02

Copyright and License Information

Copyright 2022 held by the authors

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