使用SCAN和r2SCAN函数来评估氧化物表面上被吸附的CO的振动频率
Alexander Contreras-Payares1,2, Pablo G Lustemberg1, M Verónica Ganduglia-Pirovano1
1Institute of Catalysis and Petrochemistry, ICP, Spanish National Research Council, CSIC, 28049 Madrid, Spain.
像SCAN和r2SCAN这样的Meta-GGA函数不能准确地预测表面的一氧化碳 (CO) 振动频率. 混合密度函数理论 (DFT) 对于解释实验数据至关重要.
科学领域:
- 表面科学是一门学科.
- 计算化学的计算化学
- 催化剂是一种催化剂.
背景情况:
- 吸附的一氧化碳 (CO) 的振动频率是基催化剂暴露表面面的关键指标.
- 以前的研究表明,混合DFT与HSE06是准确的,而GGA与PBE+U不是.
研究的目的:
- 对HSE06进行meta-GGA函数 (SCAN,r2SCAN) 的评估,用于预测氧化表面上的CO振动频率.
- 了解meta-GGA函数在描述吸现象上的局限性.
主要方法:
- 将SCAN和r2SCAN元GGA函数与HSE06混合DFT进行比较.
- 对氧化和减少表面的电荷定位和振动频率预测的评估.
- 调查哈伯德U热效应对电荷定位的研究.
主要成果:
- 对氧化表面的前方法而言,Meta-GGA功能没有显著改善.
- 超-GGA功能器无法准确地将过量的电荷定位在减少的表面上.
- 与HSE06.06相比,添加哈伯德U项可以改善电荷定位,但不能提高频率预测的准确性.
结论:
- 超级GGA函数不充分捕捉电子效应 (捐赠/反捐赠),这对于准确的CO吸附能量计算至关重要.
- 混合DFT,尽管计算成本较高,是不可或缺的可靠的解释实验CO振动光谱在ceria.
- 准确的二氧化碳吸附理论建模需要适当考虑不同面上的电子相互作用的方法.
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