Theoretical study on the thermodynamic and transition properties of the interstellar molecule: FeC

作     者：Fang, Nan Zhang, Chuan-Yu Wan, Ming-Jie Huang, Xiao-Peng 

作者机构：Chengdu Univ Technol Sch Math & Phys Chengdu 610059 Peoples R China Yibin Univ Computat Phys Key Lab Sichuan Prov Yibin 644000 Peoples R China 

出 版 物：《THERMOCHIMICA ACTA》 (Thermochim Acta)

年 卷 期：2025年第745卷

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0807[工学-动力工程及工程热物理] 0703[理学-化学] 

基　　金：National Natural Science Foundation of China [41930112, 91755215, 11804238] Sichuan Science and Technology Program [2022YFG0317] 

主　　题：Partition functions Thermodynamic properties Ultraviolet spectrum Rotational spectrum 

摘      要：As an interstellar molecule, the thermodynamic properties and transition characteristics of FeC hold significant importance. In this study, high-precision ab initio methods were employed to obtain the potential energy functions of the five Lambda-S states of FeC. Based on these results, the Partition functions, proportions of each molecular and thermodynamic properties were calculated for temperatures from 50 K to 10,000 K. In addition, the spin orbit coupling effects on the ground state (X 3 Delta ) split it into three Omega states (Omega = 3, 2, 1), with Omega = 3 being the lowest. The rotational spectrum for Omega = 3 at 298.15 K shows significantly higher transition intensity for the v = 0 and v = 0 band. Moreover, this paper presents the ultraviolet spectrum of two transitions: X 3 Delta 13 Pi and 13 Pi 1 3 Sigma- , at a temperature of 298.15 K, with the 13 Pi 1 3 Sigma- transition having stronger absolute intensity.