Assessing the performance of recent density functionals for bulk solids
Assessing the performance of recent density functionals for bulk solids
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DOI：
10.1103/physrevb.79.155107
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发表时间：
2009-04-01
影响因子：
3.7
通讯作者：
Angyan, Janos G.
中科院分区：
文献类型：
--
作者：
Csonka, Gabor I.;Perdew, John P.;Angyan, Janos G.
我们评估最近的密度泛函的非分子固体的交换相关能量的性能，通过应用精确的计算与高斯，波段，和VASP代码的测试集的24个固体金属和非金属。测试的泛函是修改的Perdew-Burke-Ernzerhof广义梯度近似（PBESol GGA），二阶GGA（SOGGA）和Armiento-Mattsson 2005（AM 05）GGA。为了完整性，我们还测试了更多的标准泛函：局部密度近似，原来的PBE GGA，和陶Perdew Staroverov-Scuseria元GGA。我们发现，最近的密度泛函固体达到了高精度的散装性能（晶格常数和体积模量）。正如预期的那样，对于内聚能，PBE总体上优于PBESol，但PBESol实际上对于碱金属和碱金属卤化物更好。为了公平地比较计算结果和实验结果，我们考虑了零点声子和有限温度效应被许多工作者忽略。我们将展示高斯基组和不准确的实验参考数据可能会影响评级的质量的泛函。结果表明，PBESol和AM 05对于碱金属、碱土金属和碱金属卤化物晶体的性能彼此略有不同（其中约化密度梯度的最大值约为2），但对于大多数其他固体的性能非常相似（其中约化密度梯度的最大值通常约为1）。我们对此的解释是一致的交换相关非局域性的核心价重叠的区域中的重要性。
We assess the performance of recent density functionals for the exchange-correlation energy of a nonmolecular solid, by applying accurate calculations with the GAUSSIAN, BAND, and VASP codes to a test set of 24 solid metals and nonmetals. The functionals tested are the modified Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol GGA), the second-order GGA (SOGGA), and the Armiento-Mattsson 2005 (AM05) GGA. For completeness, we also test more standard functionals: the local density approximation, the original PBE GGA, and the Tao-Perdew-Staroverov-Scuseria meta-GGA. We find that the recent density functionals for solids reach a high accuracy for bulk properties (lattice constant and bulk modulus). For the cohesive energy, PBE is better than PBEsol overall, as expected, but PBEsol is actually better for the alkali metals and alkali halides. For fair comparison of calculated and experimental results, we consider the zero-point phonon and finite-temperature effects ignored by many workers. We show how GAUSSIAN basis sets and inaccurate experimental reference data may affect the rating of the quality of the functionals. The results show that PBEsol and AM05 perform somewhat differently from each other for alkali metal, alkaline-earth metal, and alkali halide crystals (where the maximum value of the reduced density gradient is about 2), but perform very similarly for most of the other solids (where it is often about 1). Our explanation for this is consistent with the importance of exchange-correlation nonlocality in regions of core-valence overlap.