De novo design of an endohedral heteronuclear dimetallofullerene (U-Gd)@C60 with exceptional structural and electronic properties.

Ever since the first synthesis of La@C82 and U@C28 , there has been a growing interest in the study of endohedral metallofullerenes (EMFs) because of their great potential in various applications. Here we design a novel heteronuclear EMF (U-Gd)@C60 , by using density functional theory (DFT), which shows an encapsulation energy of about -5.53 eV, comparable to that of U2 @C60, La2 @C80 , and Lu2 @C76 . (U-Gd)@C60 is found to have a surprising twofold, single-electron UGd bond that results from the strong nanoconfinement of the fullerene, dominated by uranium's 5f and 6d and gadolinium's 5d atomic orbitals. The ground state shows an 11-et high spin state, and the net spins distributed on the U-pole carbons are relatively scattered, while they are highly concentrated on the Gd-pole carbons. The exceptional electronic characteristics of this novel EMF, containing both uranium and gadolinium atoms encapsulated, might prove useful for future applications in nuclear energy and biomedicine.