Fig. 5: The first principle computations and density functional theory analysis.

Differential charge distribution of NCU-1 configuration after adsorption with a Pr3+, b Dy3+, and c Al3+ with the corresponding Bader charges. The Bader charge on the metal ion is defined as qM. Optimized structures of NCU-1 and the adsorption energy of metal ions d Pr3+, e Dy3+, and f Al3+ (Pr3+, yellow; Dy3+, purple; Al3+, light blue).