Max Planck Institute for Solid State Research, Stuttgart, Germany.
Chemistry. 2012 Aug 27;18(35):10929-36. doi: 10.1002/chem.201200180. Epub 2012 Jul 16.
Recently, we have investigated the energy landscape of PbS for many different pressures on the ab initio level by using Hartree-Fock and density functional theory to globally search for possible thermodynamically stable and metastable structures. The perhaps most fascinating observation was that besides the experimentally known modification exhibiting the rock salt structure a second minimum exists close-by on the landscape showing the low-temperature α-GeTe-type structure. In the present study, we investigate the possible reasons for the existence of this metastable modification; in particular we address the question, whether the α-GeTe-type modification might be stabilized (and conversely the rock salt modification destabilized) by steric effects of the non-bonding electron pair.
最近，我们通过使用 Hartree-Fock 和密度泛函理论在从头算水平上研究了许多不同压力下的 PbS 的能量景观，以全局搜索可能的热力学稳定和亚稳结构。最吸引人的观察结果是，除了实验上已知的表现出岩盐结构的修饰外，在景观上还存在第二个近邻的最小值，显示出低温 α-GeTe 型结构。在本研究中，我们研究了这种亚稳修饰存在的可能原因；特别是，我们解决了这样一个问题，即非键电子对的位阻效应是否可以稳定（反之，岩盐修饰可以不稳定）α-GeTe 型修饰。
