Thermodynamic and radiative properties of TiO in local thermal equilibrium and non-equilibrium conditions

Abstract

The thermodynamic and radiative properties of TiO in the local thermodynamic equilibrium (LTE) and non-LTE (NLTE) were investigated. Firstly, we investigated the potential energy curves of fifteen electronic states of TiO by the icMRCI + Q method with a large aug-cc-pwCV5Z-DK basis set. Then the internal partition functions, average internal energies, specific heats at temperatures from 100 to 15,000 K in the LTE and NLTE were obtained. The contributions of different states are not affected by the condition of the gas. In addition, the transition dipole moments for eight transitions and the radiative properties (absorption and emissivity) of TiO in the LTE and NLTE were obtained. The A³Φ−X³Δ, B³Π−X³Δ and C³Δ−X³Δ transitions play a key role in the calculations of the absorption and emissivity. The absorption and emissivity in the LTE and NLTE were also calculated, and the electronic and vibrational energy highly contributes to the absorption and the translational and rotational energy highly contributes to the emissivity.

GRAPHICAL ABSTRACT

KEYWORDS:

• Thermodynamic properties
• radiative properties
• TiO

Disclosure statement

No potential conflict of interest was reported by the author(s).

Credit authorship contribution statement

Tianrui Bai: Software, Investigation, Conceptualisation, Methodology, Writing-Original Draft.

Zhi Qin: Investigation, Conceptualisation, Data curation, Review & Editing.

Linhua Liu: Supervision, Funding acquisition, Conceptualisation, Data curation, Review & Editing.

Additional information

Funding

This work is sponsored by the National Natural Science Foundation of China under grant number 51336002, 51421063. This work is also supported by the Postdoctoral Applied Research Project of Qingdao. The scientific calculations in this paper have been done on the HPC Cloud Platform of Shandong University.