Electronic structures and transition properties of AsH<sup>+</sup> cation

<sec>Potential energy curves (PECs), dipole moments (DMs) and transition (TDMs) of the X<sup>2</sup>?, a<sup>4</sup>?<sup>–</sup>, A<sup>2</sup>?<sup>–</sup>, b<sup>4</sup>?, B<sup>2</sup>?, C<sup>2</sup>?<sup>+</sup>, D<sup>2</sup>?, 2<sup>2</sup>?<sup>+</sup> states correlating with three lowest dissociation channels AsH<sup>+</sup> cation are calculated by using multireference configuration interaction (MRCI) method. The Davidson correction, core-valence (CV) correlation, spin-orbit coupling (SOC) effect all considered. aug-cc-pV5Z all-electron basis set H atom aug-cc-pwCV5Z-PP pseudopotential As both selected in calculation.</sec><sec>In complete active space self-consistent field (CASSCF) calculation, (1s) (4s4p) shell as orbitals, (3p3d) shells closed which keeps doubly occupation, remaining electrons frozen orbitals. In MRCI used for CV calculation accuracy can be improved. SOC effects considered Breit-Pauli operators.</sec><sec>All bound states. X<sup>2</sup>? is ground state, a deep potential well, 3.100 eV. C<sup>2</sup>?<sup>+</sup> D<sup>2</sup>? weakly spectroscopic parameters obtained solving radial Schrodinger equation. To best our knowledge, there has been no study spectroscopy so far. Comparing ?-hydride cations <i>M</i>H<sup>+</sup> (<i>M</i> = N, P, As), orders levels low-lying ions identical. harmonic frequency decrease increase atomic weight <i>M</i>.</sec><sec>At spin-free level, PEC b<sup>4</sup>? state B<sup>2</sup>? cross at about 1.70 Å. When taken into account, according to rule avoid-crossing, <inline-formula><tex-math id="M5">\begin{document}$ {{{\rm{B}}^2}}{\Delta _{3/2}} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="21-20221104_M5.jpg"/><graphic xlink:href="21-20221104_M5.png"/></alternatives></inline-formula>state id="M6">\begin{document}$ _{5/2}} xlink:href="21-20221104_M6.jpg"/><graphic xlink:href="21-20221104_M6.png"/></alternatives></inline-formula>state change double wells, avoided crossing between id="M7">\begin{document}$ xlink:href="21-20221104_M7.jpg"/><graphic xlink:href="21-20221104_M7.png"/></alternatives></inline-formula> (<inline-formula><tex-math id="M8">\begin{document}$ xlink:href="21-20221104_M8.jpg"/><graphic xlink:href="21-20221104_M8.png"/></alternatives></inline-formula>) id="M9">\begin{document}${{\rm{b}}^4}{\Pi _{3/2}}$\end{document}</tex-math><alternatives><graphic xlink:href="21-20221104_M9.jpg"/><graphic xlink:href="21-20221104_M9.png"/></alternatives></inline-formula> id="M10">\begin{document}${{\rm{b}}^4}{\Pi _{5/2}}$\end{document}</tex-math><alternatives><graphic xlink:href="21-20221104_M10.jpg"/><graphic xlink:href="21-20221104_M10.png"/></alternatives></inline-formula>) observed. moment (TDM) id="M11">\begin{document}$ {{{\rm{A}}^2}}{\Sigma ^ - } \to {{{\rm{X}}^2}}\Pi xlink:href="21-20221104_M11.jpg"/><graphic xlink:href="21-20221104_M11.png"/></alternatives></inline-formula>, id="M12">\begin{document}$ {{{\rm{a}}^4}}\Sigma _{1/2}^ {{{\rm{X}}^2}}{\Pi _{1/2}} xlink:href="21-20221104_M12.jpg"/><graphic xlink:href="21-20221104_M12.png"/></alternatives></inline-formula> id="M13">\begin{document}$ {{{\rm{A}}^2}}\Sigma xlink:href="21-20221104_M13.jpg"/><graphic xlink:href="21-20221104_M13.png"/></alternatives></inline-formula> also calculated. TDM equilibrium distance id="M14">\begin{document}$ xlink:href="21-20221104_M14.jpg"/><graphic xlink:href="21-20221104_M14.png"/></alternatives></inline-formula> spin-forbidden reaches 0.036 Debye, therefore, plays an important role. Based on accurate PECs PDMs, Franck-Condon factors, spontaneous radiative coefficients, lifetimes id="M15">\begin{document}$ xlink:href="21-20221104_M15.jpg"/><graphic xlink:href="21-20221104_M15.png"/></alternatives></inline-formula>, id="M16">\begin{document}$ xlink:href="21-20221104_M16.jpg"/><graphic xlink:href="21-20221104_M16.png"/></alternatives></inline-formula>, id="M17">\begin{document}$ xlink:href="21-20221104_M17.jpg"/><graphic xlink:href="21-20221104_M17.png"/></alternatives></inline-formula> calculated.</sec>