在曲模式下与原子碰撞时,二氧化碳的状态到状态旋振转率
Taha Selim1, Ad van der Avoird1, Gerrit C Groenenboom1
1Theoretical Chemistry Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
The Journal of chemical physics
|October 26, 2023
概括
我们计算了二氧化碳 (CO2) 和 (He) 碰撞的速率系数,这对于模拟原行星盘等非平衡环境至关重要. 我们的结果与实验数据有很好的一致性,并强调了准确的潜在表面的重要性.
科学领域:
- 计算化学计算化学
- 天体物理学 天体物理学
- 分子光谱学 分子光谱学
背景情况:
- 建模非局部热平衡环境 (如原行星盘,行星大气层) 需要精确的分子碰撞率系数.
- 无振动无弹性碰撞是解释来自太空望远镜的分子光谱数据的关键.
研究的目的:
- 计算二氧化碳 (CO2) 与 (He) 原子相撞的速率系数,重点关注曲模式激发/解激发.
- 为天体物理应用提供这些系数在10500K的温度范围内.
- 评估不同计算方法 (CC,CSA,VCC-IOS) 与初始计算和实验数据的准确性.
主要方法:
- 精确的初始四维CO2-He潜在表面计算,包括CO2曲 (ν2) 模式.
- 数字精确的合通道 (CC) 计算.
- 合状态近似 (CSA) 和振动密切合旋转无限顺序突然 (VCC-IOS) 方法进行比较.
主要成果:
- CSA和VCC-IOS方法为整体振动火 (低温<50K除外) 的CC结果的20%内产生速率系数.
- 来自CSA和VCC-IOS的州对州横截面与CC结果达成50%的一致,在低能量/共振下有偏差.
- 计算的CC火率与最近的实验数据有很好的一致性.
结论:
- 该研究提供了CO2-He碰撞的基本速率系数,对于天体物理学建模至关重要.
- 准确的初始电位面和CC计算对于可靠的低能碰撞动态至关重要.
- CSA和VCC-IOS方法为振动火率提供了合理的近似值,但在低温下共振效应显著.
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