Performance of the OP correlation functional in relation to its formulation: Influence of the exchange component and the effect of incorporating same-spin correlations
Performance of the OP correlation functional in relation to its formulation: Influence of the exchange component and the effect of incorporating same-spin correlations
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OP 相关函数的性能与其公式相关：交换分量的影响以及合并同旋相关的效果
DOI：
10.1002/jcc.24327
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发表时间：
2016
影响因子：
3
通讯作者：
and K. Hirao
中科院分区：
文献类型：
--
作者：
Bun Chan;J.-W. Song;Y. Kawashima;and K. Hirao
在本研究中，我们研究了OP相关泛函的两个重要特征，即将交换泛函并入自身，以及仅包含反旋（OS）效应。为了探索后一个特征，我们比较了OP与B 95以及本研究中引入的一个新泛函-OPB方法，该方法将OP与B 95的同自旋（SS）分量相结合。总的来说，我们发现B 95和OPB的表现相当。我们对各种DFT程序的比较表明，引入Meta GGA（例如，TPSS）转化为OP和OPB不一定导致比使用相关GGA（例如，PBE）。一个重要的发现是，结合SS相关性后，性能得到了更显著（也更一致）的改善，特别是对于较长范围的化学性质。尽管如此，在我们超过800个系统的测试集中，OP与B 95或OPB的性能之间的差异并不是非常大。通过将这些DFT方法与波函数标度MP2型方法进行比较，我们推断可以进一步发展OP泛函，并且通过将其与范围分离技术相结合，可能会产生更广泛的相关泛函。© 2016 Wiley Periodicals，Inc.
In the present study, we have investigated two significant features of the OP correlation functional, namely the incorporation of the exchange functional into itself, and the inclusion of only opposite‐spin (OS) effects. To explore the latter feature, we have compared OP with B95 and a new functional introduced in the present study – the OPB method that combines OP with the same‐spin (SS) component of B95. In general, we find that B95 and OPB perform comparably. Our comparisons of the various DFT procedures suggest that the incorporation of a meta‐GGA (e.g., TPSS) into OP and OPB does not necessarily lead to a chemically more accurate procedure than the use of a related GGA (e.g., PBE). An important finding is the more notable (and somewhat more consistent) improvement in performance with the incorporation of SS correlation, particularly for longer‐range chemical properties. Nonetheless, on average across our test sets of over 800 systems, the difference between the performances of OP versus B95 or OPB is not exceedingly large. By drawing a parallel between these DFT methods and the wavefunction scaled‐MP2‐type methods, we reason that one can further develop the OP functional, and perhaps a wider range of correlation functionals by combining it with the technique of range separation. © 2016 Wiley Periodicals, Inc.