Structural and electronic properties of Gd@C60: All-electron relativistic total-energy study

Water soluble Gd-based metallofullerenes have potential application as magnetic resonance imaging contrast agent due to its higher proton relaxivities and lower toxicity. In this Letter, we have investigated the structural and electronic properties of Gd@C60, which is the most abundantly produced Gd-based metallofullerene in carbon arc process, by using all-electron relativistic density functional theory. It is found that the Gd3+ ion is bonded to a hexagonal ring of C60 by electrostatic interaction. The total spin multiplicity of Gd@C60 is S = 7. The Gd atomic orbitals are hybridized with the C60 molecular orbitals.