title: Binding and Diffusion of Lithium in Graphite: Quantum Monte Carlo Benchmarks and Validation of van der Waals Density Functional Methods.
abstract: Highly accurate diffusion quantum Monte Carlo (QMC) studies of the adsorption and diffusion of atomic lithium in AA-stacked graphite are compared with van der Waals-including density functional theory (DFT) calculations. Predicted QMC lattice constants for pure AA graphite agree with experiment. Pure AA-stacked graphite is shown to challenge many van der Waals methods even when they are accurate for conventional AB graphite. Highest overall DFT accuracy, considering pure AA-stacked graphite as well as lithium binding and diffusion, is obtained by the self-consistent van der Waals functional vdW-DF2, although errors in binding energies remain. Empirical approaches based on point charges such as DFT-D are inaccurate unless the local charge transfer is assessed. The results demonstrate that the lithium-carbon system requires a simultaneous highly accurate description of both charge transfer and van der Waals interactions, favoring self-consistent approaches.
authors.affiliation: Center for Nanophase Materials Sciences, ‡Material Science and Technology Division, and §Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: P
authors.initials: P
authors.lastname: Ganesh
authors.affiliation: Center for Nanophase Materials Sciences, ‡Material Science and Technology Division, and §Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Jeongnim
authors.initials: J
authors.lastname: Kim
authors.affiliation: Center for Nanophase Materials Sciences, ‡Material Science and Technology Division, and §Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Changwon
authors.initials: C
authors.lastname: Park
authors.affiliation: Center for Nanophase Materials Sciences, ‡Material Science and Technology Division, and §Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Mina
authors.initials: M
authors.lastname: Yoon
authors.affiliation: Center for Nanophase Materials Sciences, ‡Material Science and Technology Division, and §Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Reboredo
authors.affiliation: Center for Nanophase Materials Sciences, ‡Material Science and Technology Division, and §Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Paul R C
authors.initials: PR
authors.lastname: Kent