Institute of Chemistry, University of Graz, Heinrichstrasse 28/IV, A-8010 Graz, Austria.
J Chem Phys. 2018 Sep 28;149(12):124104. doi: 10.1063/1.5046908.
We introduce and employ two QM:QM schemes (a quantum mechanical method embedded into another quantum mechanical method) and report their performance for the X23 set of molecular crystals. We furthermore present the theory to calculate the stress tensors necessary for the computation of optimized cell volumes of molecular crystals and compare all results to those obtained with various density functionals and more approximate methods. Our QM:QM calculations with PBE0:PBE+D3, PBE0:PBE+MBD, and B3LYP:BLYP+D3 yield at a reduced computational cost lattice energy errors close to the ones of the parent hybrid density functional method, whereas for cell volumes, the errors of the QM:QM scheme methods are in between the generalized gradient approximation and hybrid functionals.
我们引入并运用了两种 QM:QM 方案（一种量子力学方法嵌入到另一种量子力学方法中），并报告了它们在 X23 分子晶体数据集上的性能。我们进一步提出了计算分子晶体优化晶胞体积所需的应力张量的理论，并将所有结果与各种密度泛函和更近似方法的结果进行了比较。我们使用 PBE0:PBE+D3、PBE0:PBE+MBD 和 B3LYP:BLYP+D3 的 QM:QM 计算在降低的计算成本下，晶格能误差接近母体混合密度泛函方法的误差，而对于晶胞体积，QM:QM 方案方法的误差在广义梯度近似和混合泛函之间。
