线性Jahn-Teller耦合轨道五重态的低能激发

Second-order nonadiabatic couplings from time-dependent density functional theory: Evaluation in the immediate vicinity of Jahn-Teller/Renner-Teller intersections

For a rigorous quantum simulation of nonadiabatic dynamics of electrons and nuclei, knowledge of not only first-order but also second-order nonadiabatic couplings (NAC), is required. Here we propose a method to efficiently calculate second-order NAC from time-dependent density functional theory (TDDFT), on the basis of the Casida ansatz adapted for the computation of first-order NAC, which has been justified in our previous work and can be shown to be valid for calculating second-order NAC between ground state and singly excited states within the Tamm-Dancoff approximation. Test calculations o…

Dynamical Jahn-Teller effect in the first excited C$_{60}^-$

The Jahn-Teller effect of C$_{60}$ anions in the first electronically excited states was theoretically investigated. The orbital vibronic coupling parameters for the $t_{1g}$ next lowest unoccupied molecular orbitals were derived from the Kohn-Sham orbital levels with hybrid B3LYP functional by using the frozen phonon approach. With the use of these coupling parameters, the vibronic states of the first excited C$_{60}^-$ were derived by exactly diagonalizing the dynamical Jahn-Teller Hamiltonian. The dynamical Jahn-Teller stabilization energy of the first excited C$_{60}^-$ is stronger than th…

Dynamical Jahn-Teller effect of fullerene anions

The dynamical Jahn-Teller effect of C$_{60}^{n-}$ anions ($n = $ 1-5) is studied using the numerical diagonalization of the linear $p^n \otimes 8d$ Jahn-Teller Hamiltonian with the currently established coupling parameters. It is found that in all anions the Jahn-Teller effect stabilizes the low-spin states, resulting in the violation of Hund's rule. The energy gain due to the Jahn-Teller dynamics is found to be comparable to the static Jahn-Teller stabilization. The Jahn-Teller dynamics influences the thermodynamic properties via strong variation of the density of vibronic states with energy.…

Mechanisms of localization in isotope-substituted dynamical Jahn-Teller systems

The mechanisms of localization of Jahn-Teller deformations and vibronic wavefunctions in isotope substituted dynamical Jahn-Teller systems are elucidated. It is found that the localization in the trough is of potential type in the case of strong vibronic coupling, while it becomes of kinetic type in the case of intermediate and weak coupling. It is shown that the vibronic levels in the linear $E\otimes e$-problem remain double degenerate upon arbitrary isotope substitution on the reasons similar to time reversal symmetry in which the role of spin is played by orbital pseudospin.

Ansatz for the Jahn-Teller triplet instability

A threefold degenerate electronic state is Jahn-Teller unstable with respect to symmetry lowering distortions, which transform as the five quadrupolar modes. The solution of the corresponding vibronic Hamiltonian is constructed using the analytical method introduced by Bargmann, as an alternative to existing group-theoretical methods based on coefficients of fractional parentage. It involves the construction of an Ansatz which incorporates SO(5) to SO(3) symmetry breaking. The resulting Jahn-Teller equations are derived, and solved in terms of radial polynomials and Gegenbauer functions.

动力学Jahn-Teller系统的Berry相位与基态对称性

Berry-Phase and Symmetry of the Ground State in Dynamical Jahn-Teller Systems

我们表明，通过选定的例子，相关的物理学的富勒烯离子，Berry相的存在下，在动态Jahn-Teller系统并不能保证简并的基态，与以前认为的。此外，我们引入了一类新的Jahn-Teller系统没有Berry相位，作为基本二十面体$H \otimes h$情况的推广。