title: Insights into Li(+) Migration Pathways in α-Li3VF6: A First-Principles Investigation.
abstract: Magnetic, structural, and defect properties of lithium vanadium hexafluoride (α-Li3VF6) are investigated theoretically with periodic quantum chemical methods. It is found that the ferromagnetic phase is more stable than the antiferromagnetic phase. The crystal structure contains three inequivalent Li sites (Li(1), Li(2), and Li(3)), where Li(1) occupies the middle position of the triplet Li(2)-Li(1)-Li(3). The calculated Li vacancy formation energies show that vacancy formation is preferred for the Li(1) and Li(3) sites compared to the Li(2) position. The Li exchange processes between Li(1) ↔ Li(3), Li(1) ↔ Li(2), and Li(2) ↔ Li(3) are studied by calculating the Li(+) migration between these sites using the climbing-image nudged elastic band approach. It is observed that Li exchange in α-Li3VF6 may take place in the following order: Li(1) ↔ Li(3) > (Li(1) ↔ Li(2) > Li(2) ↔ Li(3). This is in agreement with recently published results obtained from 1D and 2D (6)Li exchange nuclear magnetic resonance spectroscopy.
authors: †Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraße 4, D-53115 Bonn, Germany.
authors: Mazharul M
authors: MM
authors: Islam
authors: ‡Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, A-8010 Graz.
authors: Martin
authors: M
authors: Wilkening
authors: Paul
authors: P
authors: Heitjans
authors: †Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraße 4, D-53115 Bonn, Germany.
authors: Thomas
authors: T
authors: Bredow
keywords: Li diffusion; activation energy; lithium vanadium fluoride; migration pathway; point defects; relaxation