Theoretical investigation on spectroscopic characteristics of 14 Λ-S and 27 Ω states of OH<sup>+</sup> cation
Authors: Xing Wei , Li Sheng-Zhou , Zhang Fang , Sun Jin-Feng , Li Wen-Tao , Zhu Zun-Lüe ,   College of Physics and Electronic Engineering, Xinyang Normal University, Xinyang 464000, China,   School of Physics, Henan Normal University, Xinxiang 453000, China,   Weifang University of Science and Technology, Shouguang 262700, China
Published: October 2024

Based on the selection of appropriate active space and basis sets, and consideration of various physical effects such as scalar relativistic effect, core-valence electron correlation, complete basis set limit and spin-orbit coupling effect, the precise ionization energy of X<sup>3</sup>Σ<sup>–</sup>/a<sup>1</sup>Δ/b<sup>1</sup>Σ<sup>+</sup>/A<sup>3</sup>Π/c<sup>1</sup>Π(OH<sup>+</sup>)←X<sup>2</sup>Π(OH), and the potential energy curves of 14 Λ-S and 27 Ω states of OH<sup>+</sup> are obtained by using the optimized icMRCI + <i>Q</i> method. The transition dipole moments between six Ω states[<inline-formula><tex-math id="M7">\begin{document}$ {\mathrm{X}}{}^3\Sigma _{{0^ + }}^{{ - }} $\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id="M8">\begin{document}$ {{\text{X}}^{3}}{{\Sigma }}_{1}^{{ - }} $\end{document}</tex-math></inline-formula>, (1)2, (2)2, (2)1, and (1)0<sup>–</sup>] are obtained by using the all electron icMRCI/cc-pCV5Z + SOC theory. The ionization energy, spectroscopic and vibrational-rotational transition data obtained in this work are in good agreement with the existing measurements. The findings in this work are as follows. 1) The radiation lifetimes of (1)2(<i>υ'</i> = 0–6, <i>J'</i> = 2, +) gradually decrease with <i>υ'</i> increasing, while the radiation widths correspondingly increase; the spontaneous emissions of (1)2(<i>υ'</i> = 0–6, <i>J'</i> = 2, +)–<inline-formula><tex-math id="M9">\begin{document}$ {\text{X}}{}^3{{\Sigma }}_1^{{ - }} $\end{document}</tex-math></inline-formula>(<i>υ''</i>, <i>J''</i> = 1, –) are weak. 2) The radiation lifetimes of (2)2<sup>1st well</sup>(<i>υ'</i> = 0–2, <i>J'</i> = 2, +), (2)1(<i>υ'</i> = 0–9, <i>J'</i> = 1, +), and (1)0<sup>–</sup>(<i>υ'</i> = 0–8, <i>J'</i> = 0, +) all gradually increase as <i>υ'</i> increases, while their radiation widths narrow with <i>υ'</i> increasing; the spontaneous emissions of (2)2<sup>1st well</sup>(<i>υ'</i> = 0–2, <i>J'</i> = 2, +)–<inline-formula><tex-math id="M10">\begin{document}$ {\text{X}}{}^3{{\Sigma }}_1^{{ - }} $\end{document}</tex-math></inline-formula>(<i>υ''</i>, <i>J''</i> = 1, –), (2)1(<i>υ'</i> = 0–9, <i>J'</i> = 1, +)–<inline-formula><tex-math id="M11">\begin{document}$ {\text{X}}{}^{3}{{\Sigma }}_{{{0}^ + }}^{{ - }} $\end{document}</tex-math></inline-formula>(<i>υ''</i>, <i>J''</i> = 1, –), and (1)0<sup>–</sup>(<i>υ'</i> = 0–8, <i>J'</i> = 0, +)–<inline-formula><tex-math id="M12">\begin{document}$ {\text{X}}{}^3{{\Sigma }}_1^{{ - }} $\end{document}</tex-math></inline-formula>(<i>υ''</i>, <i>J''</i> = 1, –) are strong. 3) The radiation lifetimes of (2)2<sup>1st well</sup>(<i>υ'</i> = 0–2, +), (2)1(<i>υ'</i> = 0–9, +), and (1)0<sup>–</sup>(<i>υ'</i> = 0–8, +) all gradually increase with <i>J'</i> increasing. The datasets presented in this work, including the potential energy curves of 14 Λ-S and 27 Ω states, 7 pairs of transition dipole moments between the 6 Ω states [<inline-formula><tex-math id="M13">\begin{document}$ {{\mathrm{X}}}^3\Sigma _{{0^ + }}^{{ - }} $\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id="M14">\begin{document}$ {\text{X}}{}^3{{\Sigma }}_1^{{ - }} $\end{document}</tex-math></inline-formula>, (1)2, (2)2, (2)1, (1)0<sup>–</sup>], and distributions of the radiative lifetime varying with the <i>J'</i> of the (2)2<sup>1st well</sup>(<i>υ'</i> = 0–2, +), (2)1(<i>υ'</i> = 0–9, +), and (1)0<sup>–</sup>(<i>υ'</i> = 0–8, +) states may be available at <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.doi.org/10.57760/sciencedb.j00213.00058">https://www.doi.org/10.57760/sciencedb.j00213.00058</ext-link>.