Karttunen Antti J, Usvyat Denis, Schütz Martin, Maschio Lorenzo
Department of Chemistry and Materials Science, Aalto University, FI-00076 Aalto, Finland.
Institut für Chemie, Humboldt Universität zu Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany.
Phys Chem Chem Phys. 2017 Mar 15;19(11):7699-7707. doi: 10.1039/c6cp08873b.
van der Waals interactions are known to play a key role in the formation of weakly bound solids, such as molecular or layered crystals. Here we show that the correct quantum-chemical description of van der Waals dispersion is also essential for a correct description of the relative stability between purely covalently-bound solids like silicon allotropes. To this end, we apply periodic local MP2 and DFT with Grimme's empirical -D3 correction to 11 experimentally determined or yet hypothetical crystalline silicon structures, including the most recently discovered silicon allotropes. Both methods provide similar energy ordering of the polymorphs, which, at the same time, noticeably deviate from the order predicted by standard DFT without an appropriate description of the van der Waals dispersion.
众所周知，范德华相互作用在弱束缚固体（如分子晶体或层状晶体）的形成中起着关键作用。在这里，我们表明，对范德华色散进行正确的量子化学描述对于正确描述纯共价键合固体（如硅的同素异形体）之间的相对稳定性也至关重要。为此，我们将周期性局域MP2方法和带有Grimme经验性-D3校正的密度泛函理论（DFT）应用于11种实验测定的或假设的晶体硅结构，包括最近发现的硅同素异形体。两种方法都给出了多晶型体相似的能量排序，同时，在没有对范德华色散进行适当描述的情况下，这一排序明显偏离了标准DFT预测的顺序。
