High-throughput crystal structure solution using prototypes

Databases of density functional theory (DFT) calculations, such as the Open Quantum Materials Database (OQMD), have paved the way for accelerated materials discovery. DFT calculations require crystal structure information as input; however, due to inherent challenges in solving a compound's structure from powder diffraction data alone, there are thousands of experimentally synthesized compounds whose structures remain unsolved. We present a rapid DFT-based structure solution method capable of resolving numerous outstanding structure solution problems at low computational cost. The method involves (1) searching inorganic compound databases for all prototypes that match known structural characteristics of the compound, such as stoichiometry, space group, and number of atoms per cell, (2) performing DFT calculations of the target composition in each of the structural prototypes, and (3) evaluating these prototypes as candidates using a combination of DFT energy and match between calculated and experimental diffraction pattern. As this approach is straightforward and inexpensive, we employ it to solve 521 previously unsolved compounds from the Powder Diffraction File, resulting in a 1.4% expansion of the set of all experimental compounds in the OQMD. DFT calculations of these compounds could yield valuable properties.