Low-temperature structural model of hcp solid C-70

Article

关键词: ORDERING TRANSITION;    C-60;    C70;    DYNAMICS;    CRYSTALS;    PHASES;   

DOI  :  10.1103/PhysRevB.57.R13969

来源: SCIE

【 摘 要 】

We report intermolecular potential-energy calculations for solid C-70 and determine the optimum static orientations of the molecules at low temperature; we find them to be consistent with the monoclinic structural model proposed by us in an earlier report [Solid State Commun. 105, 247 (1997)]. This model indicates that the C-5 axis of the molecule is tilted by an angle similar to 18 degrees from the monoclinic b axis in contrast with the molecular orientation proposed by Verheijen et al. [J. Chem. Phys. 166, 287 (1992)] where the C-5 axis is parallel to the monoclinic b axis. In this calculation we have incorporated the effective bond charge Coulomb potential together with the Lennard-Jones potential between the molecule at the origin of the monoclinic unit cell and its six nearest neighbors, three above and three below. The minimum energy configuration for the molecular orientations turns out to be at theta= 18 degrees, phi= 8 degrees, and psi= 5 degrees, where theta, phi, and psi define the molecular orientations.

【 授权许可】

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