title: Quantum-dynamical consequences of the permutation symmetry of methyl groups.
abstract: We identify the nuclear spin isomers of nitromethane (CH(3)NO(2)) and discuss how symmetry arguments may be used to determine the spectrum and eigenfunctions of the spatial and spin-dependent Hamiltonians in an elegant way. Furthermore, we explore the effect of nuclear spin on the dynamics of the methyl group induced by a time-dependent magnetic field. We demonstrate that dipolar interactions between the protons can give rise to rotation of the methyl group and show within a one-dimensional model and first order time-dependent perturbation theory that the induced motion is unidirectional and nuclear-spin selective.
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Grohmann
authors.forename: Monika
authors.initials: M
authors.lastname: Leibscher