Unveiling the Prediction of Lanthanide Binding Selectivity: Could 4f Electrons be Treated as the Core–Shell?

With the advent of artificial intelligence, the high-throughput computation provides a powerful alternative to experimental screening of extractants. However, the reliable treatment of 4f electrons remains a major bottleneck due to their highly localized and strongly correlated nature.

In this work, we systematically benchmark two prominent computational strategies including 4f-in-valence and 4f-in-core for calculating lanthanide binding selectivity. Within the 4f-in-valence framework, density functional theory (DFT) calculations yield irregular energetic trends across the lanthanide series. Multi-configurational and multi-reference methods can replicate the experimental selectivity trends, but they demand careful selection of the active space and the treatment of dynamic correlation, posing considerable computational difficulties.