Department of Chemistry, Rice University, Houston, Texas 77005, USA.
J Chem Phys. 2010 Mar 7;132(9):094103. doi: 10.1063/1.3317437.
There has been considerable recent interest in density functionals incorporating random phase approximation (RPA) ground-state correlation. By virtue of its full nonlocality, RPA correlation is compatible with exact Hartree-Fock-type exchange and describes van der Waals interactions exceptionally well [B. G. Janesko et al., J. Chem. Phys. 130, 081105 (2009); J. Chem. Phys. 131, 034110 (2009)]. One caveat is that RPA correlation contains one-electron self-interaction error, which leads to disturbingly large correlation energies in the stretched bond situation of, e.g., H(2)(+), He(2)(+), or Ne(2)(+). In the present work, we show that inclusion of second-order screened exchange rectifies the aforementioned failure of RPA correlation. We present a large number of molecular benchmark results obtained using full-range as well as long-range corrected hybrids incorporating second-order screened exchange correlation. This correction has a generally small, and sometimes undesirable, effect on RPA predictions for chemical properties, but appears to be very beneficial for the dissociation of H(2)(+), He(2)(+), and Ne(2)(+).
最近，人们对包含随机相位近似（RPA）基态相关的密度泛函产生了浓厚的兴趣。由于其完全非局域性，RPA 相关与精确的哈特ree-fock 型交换兼容，并能非常好地描述范德华相互作用[B. G. Janesko 等人，J. Chem. Phys. 130, 081105 (2009); J. Chem. Phys. 131, 034110 (2009)]。一个警告是，RPA 相关包含单电子自相互作用误差，这导致在拉伸键情况下，如 H(2)(+)、He(2)(+)或 Ne(2)(+)，出现令人不安的大相关能量。在目前的工作中，我们表明，包含二阶屏蔽交换可以纠正 RPA 相关的上述失败。我们提出了大量使用全范围和长程修正混合包含二阶屏蔽交换相关的分子基准测试结果。这种修正对化学性质的 RPA 预测通常只有很小的影响，有时甚至是不期望的，但对于 H(2)(+)、He(2)(+)和 Ne(2)(+)的解离似乎非常有益。
