Colorado School of Mines, Golden, Colorado 80401, USA.
National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
Phys Rev Lett. 2016 Feb 19;116(7):075503. doi: 10.1103/PhysRevLett.116.075503.
Polymorphism offers rich and virtually unexplored space for discovering novel functional materials. To harness this potential approaches capable of both exploring the space of polymorphs and assessing their realizability are needed. One such approach devised for partially ionic solids is presented. The structure prediction part is carried out by performing local density functional theory relaxations on a large set of random supperlattices (RSLs) with atoms distributed randomly over different planes in a way that favors cation-anion coordination. Applying the RSL sampling on MgO, ZnO, and SnO_{2} reveals that the resulting probability of occurrence of a given structure offers a measure of its realizability explaining fully the experimentally observed, metastable polymorphs in these three systems.
多晶型现象为发现新型功能材料提供了丰富且几乎尚未开发的空间。为了利用这一潜力，需要开发能够探索多晶型空间并评估其实现可能性的方法。本文介绍了一种针对部分离子固体的方法。结构预测部分通过对一组随机超晶格（RSL）进行局部密度泛函理论松弛来完成，其中原子以有利于阳离子-阴离子配位的方式随机分布在不同的平面上。在 MgO、ZnO 和 SnO2 上应用 RSL 采样揭示了给定结构出现的概率提供了其实现可能性的度量，充分解释了这三个体系中实验观察到的亚稳多晶型。
