平面波与相关性一致的基准集:在完整的基准集极限中,MP2非共价相互作用能量的比较
Justin Villard1, Martin P Bircher2, Ursula Rothlisberger1
1Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Journal of chemical theory and computation
|December 4, 2023
概括
这项研究提出了一种用于计算量子化学中的电子相关能量的新方法,在没有外推的情况下获得准确的结果. 这些发现表明,局部基础集可能对大型系统有局限性.
科学领域:
- 量子化学 是一个量子化学.
- 计算物理 计算物理
- 理论化学 理论化学
背景情况:
- 第二阶梅勒-普莱塞特扰动理论 (MP2) 对于量子化学计算中的电子相关性至关重要.
- 准确的关联能量往往需要推断到完整的基础集 (CBS) 极限.
- 以原子为中心的基数组可能会遭受基数组叠加错误 (BSSE),特别是在弱键系系统中.
研究的目的:
- 从S22数据集中为20个二极管系统,在CBS极限中呈现非共价相互作用能量,不含BSSE.
- 为了比较平面波伪电位MP2计算与局部化 (aug-) cc-pV[D,T,Q,5]Z基和它们的推断CBS估计.
- 评估MP2能量的13种不同推断方案的性能.
主要方法:
- 使用平面波伪潜在分子动力学 (CPMD) 的高度并行MP2实现.
- 在S22数据集中,对20个二度系统进行了计算.
- 结果与局部相关性一致的基准集和各种推断技术进行了比较.
主要成果:
- 经BSSE校正的aug-cc-pV5Z基础集计算显示,与CBS平面波值 (平均绝对偏差为~0.05kcal/mol) 在没有额外推算的情况下具有很高的一致性.
- 在使用D和T点的 (aug-) cc-pVXZ基上,X-3 推断方案表现最好.
- 提出了一个新的外推方案,[公式],作为DTQ,TQ5或DTQ5数据点的总能量的可靠替代方案.
结论:
- 平面波MP2计算提供了无BSSE的CBS极限能量.
- 局部化基数集,即使是外推,对于具有大量电子的系统,也可能面临精度限制.
- 经BSSE校正的aug-cc-pV5Z基数组为准确的MP2能量提供了一个可行的替代方案.
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