The N2-, O2, and air-broadened halfwidths of CH3CN lines in the parallel ν4 band have been calculated, along with the relaxation matrices W. These calculations employ our modified and refined versions of the Robert-Bonamy formalism and use all potential parameters from the literature without adjustments. Extensive comparisons between the predicted N2-broadened halfwidths in the qR and qP branches from the models at T = 296 K and experimental measurements are presented, showing that our latest model very closely matches the measurements. For the qQ branch, where measurements are unavailable, we compare our N2-broadened halfwidths with the converted air-broadened data from HITRAN 2008, obtaining similarly good agreement. The variation in the j and k dependencies of the N2-broadened halfwidths is discussed in detail. Additionally, the theoretically determined conversion factor from N2- to air-broadening is provided. Finally, based on our theoretical calculations of N2-broadened halfwidths of the qR(j,3) lines at five different temperatures, ranging from 250 K to 350 K, the temperature exponent N is determined and its dependence on j is analyzed.

中文翻译：

---

CH3CN 分子的 N2-、O2-和空气展宽半幅宽的 j 和 k 依赖性


计算了平行 ν4 带中 CH3CN 线的 N2-、O2 和空气展宽半宽，以及松弛矩阵 W。这些计算采用了我们修改和改进的 Robert-Bonamy 形式主义版本，并使用文献中的所有潜在参数，无需调整。在 T = 296 K 时，模型和 qP 分支中预测的 N2 展宽半宽在模型和实验测量中进行了广泛的比较，表明我们的最新模型与测量值非常接近。对于无法进行测量的 qQ 分支，我们将 N2 展宽半宽与 HITRAN 2008 中转换的空气展宽数据进行比较，获得同样良好的一致性。详细讨论了 N2 展宽半宽的 j 和 k 依赖关系的变化。此外，还提供了从 N2- 到空气展宽的理论确定的转换因子。最后，基于我们对 250 K 至 350 K 的 5 种不同温度下 qR（j，3） 线的 N2 展宽半宽的理论计算，确定了温度指数 N 并分析了其对 j 的依赖性。