Tolerance Factor, Phase Stability and Order-Disorder of the Pyrochlore Structure
Tolerance factor is a structural indicator that connects crystal structure and chemical composition. In this work, we establish the tolerance factor for pyrochlore A2B2O7-type compounds, using ionic radii of the compositional species. It is derived following similar procedures as those of perovskite and garnet structures. More than 180 A2B2O7- type compounds are examined to test its validity in predicting the pyrochlore phase stability. It can also be used to understand the reverse and order-disorder cationic occupation. This structural descriptor could be used together with machine learning or high-throughput screening methods for new material design and discovery.