Violating the isolated pentagon rule (IPR): endohedral non-IPR C98 cages of Gd2@C98.

The geometric, electronic structure, and thermodynamic stability of large gadolinium-containing endohedral metallofullerenes, Gd(2)@C(98), have been systematically investigated by comprehensive density functional theory calculations combined with statistical mechanics treatments. The Gd(2)@C(2)(230924)-C(98) structure, which satisfies the isolated-pentagon rule (IPR), is determined to possess the lowest energy followed with some stable non-IPR isomers. In order to clarify the relative stabilities at elevated temperatures, entropy contributions are taken into account on the basis of the Gibbs energy at the B3LYP level for the first time.

Dangling bond-induced graphitization process on the (111) surface of diamond nanoparticles.

The intrinsic mechanism of graphitization occurring on the (111) surface of nanodiamonds (NDs) during the transformation from NDs into bucky diamonds are explored using density functional theory (DFT) computations in conjunction with density functional based tight-binding simulations. The DFT results indicate that dangling bonds (DBs) on the ND surfaces play an important role in the graphitization process, and the orientation of the DBs on different ND surfaces determines whether there will be a graphitization process or not. Moreover, a criterion is proposed to estimate rupturing of the C-C bonds between different layers on the [111] direction in the NDs and is verified to be applicable to illustrate the phase transformation from sp(3) into sp(2) bonding structures.