The single-sheeted potential energy surface (PES) of ${{\mathrm{H}}_2\mathrm{S}}^{+}\left(X{}^2{A}^{\prime \prime }\right)$ is developed based on the ab initio energies calculated by the multi-reference configuration interaction method including the Davidson correction. All the ab initio energies are first calculated using aug-cc-pVQdZ and aug-cc-pV5dZ basis sets, which are then extrapolated to the complete basis set (CBS) limit. A switching function is developed to model the transition of ${\mathrm{S}}^{+}\left({}^2\mathrm{D}\right)$ to ${\mathrm{S}}^{+}\left({}^4\mathrm{S}\right)$. The many-body expansion formalism is employed to obtain the ${{\mathrm{H}}_2\mathrm{S}}^{+}\left(X{}^2{A}^{\prime \prime }\right)$ PES by fitting such CBS energies and the root-mean square derivation is 0.0367 eV. The topographical features of the present PES are examined in detail, which are well consistent with previous studies. The quasiclassical trajectory method is subsequently utilized to study the ${\mathrm{S}}^{+}\left({}^{2}D\right)+{\mathrm{H}}_2\left(X^1{\mathrm{\Sigma }}_g^{+}\right)\to {\mathrm{S}\mathrm{H}}^{+}\left(X{}^3{\mathrm{\Sigma }}^{-}\right)+\mathrm{H}\left({}^{2}S\right)$ reaction. The capture time, integral cross sections, and rovibrational distributions are calculated. By examining the capture time, it can be concluded that the title reaction is mainly controlled by the indirect mechanism for lower collision energies, while the direct and indirect mechanisms coexist and the latter plays a dominant role for higher collision energies.

中文翻译：

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H2S +（X2A''）的精确势能面通过外推至完全基集极限，及其在S +（D2）+ H2（X1Σg+）反应动力学研究中的应用

单层势能面（PES） ${{\mathrm{H}}_{\mathrm{2个}}\mathrm{小号}}^{+}（X{}^{\mathrm{2个}}{\mathrm{一个}}^{\prime \prime }）$基于通过包括戴维森校正的多参考配置相互作用方法计算的从头算起的能量来开发。首先使用aug-cc-pV Q dZ和aug-cc-pV5dZ基础集计算所有从头算起的能量，然后将其外推到完整基础集（CBS）极限。开发了一个开关功能来模拟${\mathrm{小号}}^{+}\left({}^{\mathrm{2个}}\mathrm{d}\right)$ 到 ${\mathrm{小号}}^{+}\left({}^4\mathrm{小号}\right)$。应用多体扩展形式主义来获得${{\mathrm{H}}_{\mathrm{2个}}\mathrm{小号}}^{+}（X{}^{\mathrm{2个}}{\mathrm{一个}}^{\prime \prime }）$通过拟合这样的CBS能量，PES的均方根推导为0.0367 eV。详细检查了本PES的地形特征，这与以前的研究非常吻合。准经典轨迹法随后被用于研究${\mathrm{小号}}^{+}\left({}^{\mathrm{2个}}d\right)+{\mathrm{H}}_{\mathrm{2个}}（X^{\mathrm{1个}}{\mathrm{\Sigma }}_G^{+}）\to {\mathrm{小号}\mathrm{H}}^{+}（X{}^3{\mathrm{\Sigma }}^{-}）+\mathrm{H}（{}^{\mathrm{2个}}\mathrm{小号}）$反应。计算捕获时间，积分横截面和振动分布。通过考察捕获时间，可以得出结论：标题反应主要受间接机制降低碰撞能量的控制，而直接机制和间接机制共存，后者在较高碰撞能量中起主导作用。