Abstract

The development of an international consensus on the need to pay attention to conserving our fragile planet has inspired many computational research efforts in the condensed matter community. While several of these effort focus on predicting new materials, another approach focuses on detailed analyses of the properties of known materials. This latter approach, while often more of academic interest not necessarily leading to promising technological breakthroughs, is important for determining and refining the relationships of simulation techniques to modeling properties of real material. This talk presents the example study of the alkali-metal hexathiohypodiphosphate materials Li4P2S6 and Na4P2S6 and their alloys which are of interest to the effort of developing all solid state batteries. While Li4P2S6 has been identified as an unwanted decomposition product in the preparation of lithium thiophosphate electrolytes with very poor ionic conductivity, Na4P2S6 appears to be a competitive electrolyte for sodium ion batteries. With the help of Yan Li (WFU) and Zach Hood (ANL) as well as several others, the study of these compounds over several years has finally lead to a plausible understanding of their structures and properties. Ref. Phys. Rev. Materials 4, 045406 (2020).