title: Dynamical hydrogen atom tunneling in dichlorotropolone: a combined quantum, semiclassical, and classical study.
abstract: Based on the Cartesian Reaction Surface framework we construct a four-dimensional potential for the tropolone derivative 3,7-dichlorotropolone, a molecule with an intramolecular O-H...O hydrogen bond. The reduced configuration space involves the in-plane hydrogen atom coordinates, a symmetric O-O vibrational mode, and an antisymmetric mode related to deformations of the seven-membered ring. The system is characterized in terms of quantum mechanical computations of the low-lying eigenstates as well as a classical and semiclassical analysis of spectra obtained via Fourier transforming autocorrelation functions. For the semiclassical analysis we utilize the amplitude-free correlation function method [K. Hotta and K. Takatsuka, J. Phys. A 36, 4785 (2003)]. Our results demonstrate substantial anharmonic couplings leading to highly correlated wave functions even at moderate energies. Furthermore, the importance of dynamical tunneling in tropolone is suggested since many low-lying states--including the ground state--lie above the classical saddle point but nevertheless appear as split pairs.
authors.affiliation: Institut für Chemie, Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Giese
authors.forename: H
authors.initials: H
authors.lastname: Ushiyama
authors.forename: K
authors.initials: K
authors.lastname: Takatsuka
authors.forename: O
authors.initials: O
authors.lastname: Kühn