Despite that the tricarbon monosulfide (C3S) is among the first sulfur-containing carbon-chain molecules to be detected in the interstellar medium, no studies focused on the determination of its collisional rates. These rate coefficients are essential to estimate the abundance of C3S in the interstellar medium. Computations of the C3S( $^{1}\Sigma^{+}$ ) downward rate coefficients, induced by collision with He, are performed by averaging the integral cross sections at low temperature (below $25~\text{K}$ ). Calculations of the cross sections in the close-coupling quantum time independent formalism for $E_{c}\leq110~\text{cm}^{-1}$ and $J\leq10$ are based on a new 2-D potential energy surface. This PES is obtained from the explicit correlated coupled cluster with a single, double and perturbative triple excitation [ccsd(t)-f12] ab initio approach and the aug-cc-pVTZ basis sets. The PES have a global minimum of $-55.69~\text{cm}^{-1}$ located at $R=6.25$ bohr and $\theta=94^{\circ}$ , and a second minimum of $-36.95~\text{cm}^{-1}$ at $R=9.35$ bohr and $\theta=0^{\circ}$ . A comparison of C3S rates with those of the isoelectronic molecule C3O was made. The results indicate a great temperature dependence of the rates for transitions of $\Delta J>2$ . We expect that the new collisional data will allow for accurate determination of the C3S abundance in several interstellar regions.

中文翻译：

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一硫化三碳 (C3S) 与 (He) 碰撞的旋转去激发：势能面和速率

尽管一硫化三碳 (C3S) 是在星际介质中最早检测到的含硫碳链分子之一，但没有研究关注其碰撞率的确定。这些速率系数对于估计星际介质中 C3S 的丰度是必不可少的。由与 He 碰撞引起的 C3S( $^{1}\Sigma^{+}$ ) 向下速率系数的计算是通过在低温（低于 $25~\text{K}$ ）对积分截面进行平均来计算的. $E_{c}\leq110~\text{cm}^{-1}$ 和 $J\leq10$ 的紧密耦合量子时间无关形式的横截面计算基于新的二维势能表面。该 PES 是从显式相关耦合集群中获得的，具有单个，双重和微扰三重激励 [ccsd(t)-f12] 从头算方法和 aug-cc-pVTZ 基组。PES 的全局最小值为 $-55.69~\text{cm}^{-1}$，位于 $R=6.25$ bohr 和 $\theta=94^{\circ}$ ，第二个最小值为 $- 36.95~\text{cm}^{-1}$ 在 $R=9.35$ bohr 和 $\theta=0^{\circ}$ 。对 C3S 速率与等电子分子 C3O 的速率进行了比较。结果表明，$\Delta J>2$ 的转变速率与温度有很大的关系。我们预计新的碰撞数据将允许准确确定几个星际区域的 C3S 丰度。对 C3S 速率与等电子分子 C3O 的速率进行了比较。结果表明，$\Delta J>2$ 的转变速率与温度有很大的关系。我们预计新的碰撞数据将允许准确确定几个星际区域的 C3S 丰度。对 C3S 速率与等电子分子 C3O 的速率进行了比较。结果表明，$\Delta J>2$ 的转变速率与温度有很大关系。我们预计新的碰撞数据将允许准确确定几个星际区域的 C3S 丰度。