title: Dynamical Jahn-Teller effect and antiferromagnetism in Cs3C60.
abstract: The dynamical Jahn-Teller effect on fullerene sites in insulating Cs(3)C(60) is investigated fully ab initio. The vibronic excitations of rotational type are at ≥ 65 cm(-1), while the net kinetic contribution to the Jahn-Teller stabilization energy constitutes approximately 90 meV. This means that no localization of distortions by intermolecular interactions is possible in these fullerides; therefore, free rotations of deformations take place independently on each C(60). The latter destroy the orbital ordering and establish a conventional exchange interaction between S = 1/2 on fullerene sites. The corresponding exchange model is derived and predicts the Néel temperature for A15 Cs(3)C(60) close to experiment.
authors: Division of Quantum and Physical Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
authors: Naoya
authors: N
authors: Iwahara
authors: Liviu F
authors: LF
authors: Chibotaru