Materials Informatics Tools to Analyze Crystal Structures: Crystal Structure of the Novel Ternary Indide ErCo2In, the “Perovskite” of Intermetallics

A new ternary rare-earth indide, ErCo2In, was synthesized by arc-melting and subsequent annealing at 1070 K for 720 h. The compound extends the RECo2In (RE = Y, Pr, Nd, Sm, Gd, Tb, Dy, Ho) series. Single-crystal X-ray diffraction revealed ErCo2In to crystallize in the TbCo2In-type (a coloring variant of the PrCo2Ga-type) structure type in oP8, space group Pmma, Wyckoff sequence f2ea, а = 4.999(4), b = 4.029(3) and c = 7.078(5) Å. The crystal structure characterization with X-ray methods was further supplemented with DFT and materials informatics methods. The Crystal Bond Analyzer (CBA) was developed as a user-prompt materials informatics software for high-throughput system analysis. CBA allows visual exploration of bonding in binary and ternary systems and it reveals for ErCo2In the prevalence of the RE-Co interactions in RE–Co–In systems with the mid-range-rare-earth metals (up to Er), while the RE–Co–In systems with RE beyond Er have the prevalence of Co-In interactions.