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arXiv 1502.01100cond-mat.mtrl-sci
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密度泛函理论在纳米结构气体吸附材料预测中的作用

The Role of Density Functional Theory Methods in the Prediction of Nanostructured Gas-Adsorbent Materials

Claudio Cazorla

摘要:

随着新的合成和大规模生产技术的出现,纳米结构的气体吸附材料(GAM),如碳纳米复合材料和金属有机框架,在我们的日常生活中变得越来越有影响力。基于密度泛函理论(DFT)的第一性原理方法在建立GAM的合理设计中起着关键作用,这一因素极大地促进了GAM的发展。然而,DFT方法并不完美,并且由于GAM建模中要求的严格的精度阈值(即,精确的结合能在~ 0.01eV内),这些技术在某些具有挑战性的情况下可能提供错误的结论。有问题的情况包括气体吸附过程,其中电子长程交换和非局域相关性都很重要,以及不能忽视多体能量和库仑屏蔽效应的系统。在这篇重要的评论中,我们分析了最近在评估DFT方法在预测和理解GAM中的性能方面所做的努力。我们的调查限于氢存储和碳捕获和封存领域,为此我们暴露了一些未解决的建模争议,并定义了一套最佳实践模拟原则。此外,我们确定的DFT基准研究中发现的问题,在模型集群系统的推广到真正的材料,并讨论有效的方法来规避它们。在气体吸附现象的模拟DFT方法的优势和不完善的认识不断提高,应导致在中期更精确,因此更富有成效,从头工程的GAM。

英文摘要:

With the advent of new synthesis and large-scale production technologies, nanostructured gas-adsorbent materials (GAM) like carbon nanocomposites and metal-organic frameworks are becoming increasingly more influential in our everyday lives. First-principles methods based on density functional theory (DFT) have been pivotal in establishing the rational design of GAM, a factor which has tremendously boosted their development. However, DFT methods are not perfect and due to the stringent accuracy thresholds demanded in modelling of GAM (i.e., exact binding energies to within ~0.01 eV) these techniques may provide erroneous conclusions in some challenging situations. Examples of problematic circumstances include gas-adsorption processes in which both electronic long-range exchange and nonlocal correlations are important, and systems where many-body energy and Coulomb screening effects cannot be disregarded. In this critical review, we analyse recent efforts done in the assessment of the performance of DFT methods in the prediction and understanding of GAM. Our inquiry is constrained to the areas of hydrogen storage and carbon capture and sequestration, for which we expose a number of unresolved modelling controversies and define a set of best practice simulation principles. Also, we identify the subtle problems found in the generalization of DFT benchmark studies performed in model cluster systems to real materials, and discuss effective approaches to circumvent them. The increasing awareness of the strengths and imperfections of DFT methods in the simulation of gas-adsorption phenomena should lead in the medium term to more precise, and hence even more fruitful, ab initio engineering of GAM.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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