Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
Phys Chem Chem Phys. 2012 Jun 7;14(21):7739-43. doi: 10.1039/c2cp24090d. Epub 2012 Mar 8.
We show that the quality of density functional theory (DFT) predictions for the relative stabilities of polymorphs of crystalline para-diiodobenzene (PDIB) is dramatically improved through a simple two-body correction using wavefunction-based electronic structure theory. PDIB has two stable polymorphs under ambient conditions, and like Hongo et al. [J. Phys. Chem. Lett., 1, 1789 (2010)] we find that DFT makes wildly variable predictions of the relative stabilities, depending on the approximate functional used. The two-body corrected scheme, using Grimme's spin-scaled variant of second-order Møller-Plesset perturbation theory and any of the tested density functionals, predicts the α-polymorph to be more stable, consistent with experiment, and produces a relative stability that agrees with the benchmark quantum Monte-Carlo results of Hongo et al. within statistical uncertainty.
我们表明，通过使用基于波函数的电子结构理论进行简单的双体修正，可以显著提高密度泛函理论（DFT）对结晶对二碘苯（PDIB）多晶型体相对稳定性预测的质量。在环境条件下，PDIB 有两种稳定的多晶型体，与 Hongo 等人[J. Phys. Chem. Lett.，1，1789（2010）]一样，我们发现 DFT 对相对稳定性的预测差异很大，具体取决于所使用的近似函数。使用 Grimme 的自旋标度二阶 Møller-Plesset 微扰理论变体和任何经过测试的密度泛函的双体修正方案，预测α-多晶型体更稳定，与实验一致，并产生与 Hongo 等人的基准量子蒙特卡罗结果在统计不确定性内一致的相对稳定性。
