Accuracy of density functional theory in predicting formation energies of ternary oxides from binary oxides and its implication on phase stability
Accuracy of density functional theory in predicting formation energies of ternary oxides from binary oxides and its implication on phase stability
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DOI：
10.1103/physrevb.85.155208
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发表时间：
2012-04-30
影响因子：
3.7
通讯作者：
Ceder, Gerbrand
中科院分区：
文献类型：
--
作者：
Hautier, Geoffroy;Ong, Shyue Ping;Ceder, Gerbrand
使用密度泛函理论（DFT）评估固体之间的反应能在许多技术领域具有实际重要性，并且在已知和预测化合物的相稳定性研究中至关重要。在这项工作中，我们提出了一个比较实验提供的反应能量和DFT计算的广义梯度近似（GGA），使用哈伯德U参数的一些过渡金属元素（GGA + U）。我们使用了135个反应的数据集，涉及形成三元氧化物从二元氧化物在广泛的化学和晶体结构。我们发现，计算误差可以建模的平均值接近于零，标准偏差为24毫电子伏/原子的正态分布。显着较小的误差相比，更常见的报告错误的形成能量的元素是有关的更大的消除错误的能量时，反应涉及化学相似的化合物。这一结果对于相图计算是重要的，对于相图计算，相关的反应能量通常不是来自元素，而是来自化学上接近的相（例如，三元氧化物对比二元氧化物）。此外，我们讨论了化学之间的计算误差的分布，并表明，使用哈伯德U参数是至关重要的准确性，涉及过渡金属的反应能量，即使在正式氧化态没有发生重大变化。
The evaluation of reaction energies between solids using density functional theory (DFT) is of practical importance in many technological fields and paramount in the study of the phase stability of known and predicted compounds. In this work, we present a comparison between reaction energies provided by experiments and computed by DFT in the generalized gradient approximation (GGA), using a Hubbard U parameter for some transition metal elements (GGA + U). We use a data set of 135 reactions involving the formation of ternary oxides from binary oxides in a broad range of chemistries and crystal structures. We find that the computational errors can be modeled by a normal distribution with a mean close to zero and a standard deviation of 24 meV/atom. The significantly smaller error compared to the more commonly reported errors in the formation energies from the elements is related to the larger cancellation of errors in energies when reactions involve chemically similar compounds. This result is of importance for phase diagram computations for which the relevant reaction energies are often not from the elements but from chemically close phases (e.g., ternary oxides versus binary oxides). In addition, we discuss the distribution of computational errors among chemistries and show that the use of a Hubbard U parameter is critical to the accuracy of reaction energies involving transition metals even when no major change in formal oxidation state is occurring.