Distance-including rigorous upper bounds and tight estimates for two-electron integrals over long- and short-range operators
Distance-including rigorous upper bounds and tight estimates for two-electron integrals over long- and short-range operators
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DOI:
10.1063/1.4994190
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发表时间:
2017-10-14
影响因子:
4.4
通讯作者:
Ochsenfeld, Christian
中科院分区:
文献类型:
--
作者:
Thompson, Travis H.;Ochsenfeld, Christian
We introduce both rigorous and non-rigorous distance-dependent integral estimates for four-center two-electron integrals derived from a distance-including Schwarz-type inequality. The estimates are even easier to implement than our so far most efficient distance-dependent estimates [S. A. Maurer et al., J. Chem. Phys. 136, 144107 (2012)] and, in addition, do not require well-separated chargedistributions. They are also applicable to a wide range of two-electron operators such as those found in explicitly correlated theories and in short-range hybrid density functionals. For two such operators with exponential distance decay [e(-r12) and erfc(0.11 . r(12))/r(12)], the rigorous bound is shown to be much tighter than the standard Schwarz estimate with virtually no error penalty. The non-rigorous estimate gives results very close to an exact screening for these operators and for the long-range 1/r(12) operator, with errors that are completely controllable through the integral screening threshold. In addition, we present an alternative form of our non-rigorous bound that is particularly well-suited for improving the PreLinK method [J. Kussmann and C. Ochsenfeld, J. Chem. Phys. 138, 134114 (2013)] in the context of short-range exchange calculations. Published by AIP Publishing.