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混合量子/经典计算在CO + CO系统中旋转不弹性散射:与完全量子结果进行比较
Dulat Bostan1, Bikramaditya Mandal1, Carolin Joy1
1Chemistry Department, Marquette University, Milwaukee, Wisconsin 53201-1881, USA. dmitri.babikov@mu.edu.
Physical chemistry chemical physics : PCCP
|December 20, 2023
概括
对一氧化碳 (CO) +CO碰撞的新潜在能量表面与以前的版本的差异很小. 混合量子/经典理论 (MQCT) 准确地预测了动态,除了在量子效应占主导地位的非常低的能量之外.
科学领域:
- 化学物理 化学物理
- 分子动力学分子动力学
- 计算化学计算化学
背景情况:
- 准确的潜在能量表面 (PES) 对于理解分子相互作用至关重要.
- 以前的CO + CO PES已被广泛使用,但可能需要改进,特别是在非对称区域.
研究的目的:
- 为了呈现更新的CO + CO潜在能量表面,改进了非对称的行为.
- 将新的PES与现有表面进行比较,并评估其对动态的影响.
- 为了验证混合量子/经典理论 (MQCT) 模拟CO + CO无弹性散射.
主要方法:
- 开发了更新的CO + CO潜在能量表面,采用了改进的非对称处理.
- 通过分析函数扩展来量化新 PES 与以前 PES 之间的差异.
- 使用MQCT程序进行了不弹性散射计算.
- 将MQCT结果与全量子合状态计算进行比较.
主要成果:
- 更新后的PES与现有表面的差异很小,只有在排斥区域的高能量时才有明显的差异.
- MQCT准确地预测了 CO + CO 碰撞在更高的能量和强过渡的状态到状态过渡截面.
- 由于共振效应和较弱的过渡,MQCT在非常低的碰撞能量下显示了与全量子计算的偏差.
结论:
- 更新后的CO + CO PES提供了更精细的描述,特别是对于非对称相互作用.
- MQCT是CO+CO动态的可靠方法,特别是在较高的碰撞能量下.
- 为了捕捉非常低的碰撞能量的共振现象,需要进行全量子计算.
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