title: Electron affinity of (7)Li calculated with the inclusion of nuclear motion and relativistic corrections.
abstract: Explicitly correlated Gaussian functions have been used to perform very accurate variational calculations for the ground states of (7)Li and (7)Li(-). The nuclear motion has been explicitly included in the calculations (i.e., they have been done without assuming the Born-Oppenheimer (BO) approximation). An approach based on the analytical energy gradient calculated with respect to the Gaussian exponential parameters was employed. This led to a noticeable improvement of the previously determined variational upper bound to the nonrelativistic energy of Li(-). The Li energy obtained in the calculations matches those of the most accurate results obtained with Hylleraas functions. The finite-mass (non-BO) wave functions were used to calculate the alpha(2) relativistic corrections (alpha=1c). With those corrections and the alpha(3) and alpha(4) corrections taken from Pachucki and Komasa [J. Chem. Phys. 125, 204304 (2006)], the electron affinity (EA) of (7)Li was determined. It agrees very well with the most recent experimental EA.
authors.affiliation: Department of Chemistry, University of Arizona, Tucson, Arizona 85721 and Institute of Physics, Nicholas Copernicus University, ulica Grudziadzka 5, PL 87-100 Toruń, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Stanke
authors.forename: Dariusz
authors.initials: D
authors.lastname: Kedziera
authors.forename: Sergiy
authors.initials: S
authors.lastname: Bubin
authors.forename: Ludwik
authors.initials: L
authors.lastname: Adamowicz