Infrared spectra of a K4C60 single-phase thin film have been measured between room temperature and 20 K. At low temperatures, the two high-frequency T1u modes appear as triplets, indicating a static D2h crystal-field stabilized Jahn-Teller distortion of the C60 42 anions. The T1u(4) mode changes into a known doublet above 250 K, a pattern which could have three origins: a dynamic Jahn-Teller ef...

A new method is presented to describe deformations of an N-membered planar ring (N-ring) molecule in terms of deformation vectors that can be expressed by a set of 2N-3 deformation amplitudes and phase angles. The deformation coordinates are directly derived from the normal vibrational modes of the N-ring and referenced to a regular polygon (N-gon) of unit length. They extend the conceptual app...

The results of calculations on static Jahn-Teller ground state splittings inicosahedral C 60 ðN 1⁄4 1; . . . ; 4Þ fullerene anions with different types of electron-electron interaction are presented. Multielectron states of anions are determined within a quasy-p-electronic model configuration interaction (CI) method for two active spaces of t1u and t1uþ t1g molecular orbitals. Electron–lattice ...

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; the...

Quantifying the effect of vegetation dynamics on the climate of the Last Glacial Maximum A. Jahn, M. Claussen, A. Ganopolski, and V. Brovkin Potsdam Institute for Climate Impact Research (PIK), P.O. Box 601203, 14412 Potsdam, Germany Institute of Physics, Potsdam University, P.O. Box 601543, 14415 Potsdam, Germany now at: Department of Atmospheric and Oceanic Sciences, McGill University, Burnsi...

The laser excited, jet-cooled Ã2A′′ 2 − X̃2E′′ 1 electronic spectrum of the cyclopentadienyl radical yields detailed information about the vibronic structure of both its à and X̃ states. A straight-forward assignment of the à vibronic structure is presented. The X̃ state vibronic structure reveals a comprehensive picture of the Jahn-Teller distortion of its potential energy surface. The molecular ...