title: Non-Born-Oppenheimer approximation for very weakly bound states of molecular anions.
abstract: The influence of nuclear rotation on weak electron binding in the long range field of a linear polar molecule is treated in a way that leads ultimately, with suitable approximation, to the familiar equations for close coupling of electron-nuclear-rotational motions. Subsequently, a conventional pseudopotential approximation is invoked to examine the rotational spectra of HCN and DCN anions. It is shown that the number of rotationally excited anion states cannot be reliably predicted by assuming that zero binding occurs when the rotational energy equals the electron affinity obtained in the Born-Oppenheimer approximation. A method is suggested for combining accurate molecular orbital and parameterized pseudopotential methods to provide accurate electron affinities for very weakly bound anionic states.
authors.affiliation: Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA. wrg@utk.edu
authors.forename: W R
authors.initials: WR
authors.lastname: Garrett